distinguished by the presence of a large round sucker on the belly, with
which they adhere to rocks. Furthermore, the sucker-fishes are remarkable
for the softness of their skeleton, which may be cut through at any point
with an ordinary knife. The male lump-sucker is smaller than the female,
but much more brightly coloured, especially during the breeding-season,
when he dons a livery of blue, scarlet, and yellow. He is also a model
parent, always remaining near the eggs and keeping a constant stream of
fresh water running over them by the action of his breast-fins. A single
female may produce as many as 136,000 eggs in a single season. In Scotland
the male is known as the COCK and the female as the HEN PADDLE. The species
is more common off the coasts of Scotland than elsewhere in the British
Islands.
Like the Lump-suckers, the GOBIES, which form the next family, have the
ventral fins modified so as to form a sucking-disk, which is used as an
anchor. But the gobies are easily distinguished by their smaller size,
elongated bodies, hard skeleton, and the disposition and structure of the
fins, characters which need not be discussed further.
One species, the SPOTTED GOBY, or POLE-WING, found in the Thames, is
noteworthy on account of its nest-building habits. The male chooses the
empty shell of a cockle or mussel, selecting one with its concave surface
downwards. Beneath this the sand is cleared away and cemented by a special
glue-like secretion formed by the skin of the fish. A cylindrical tunnel is
then built to give access to the nest, and the whole is covered over with
loose stones. In the nest-chamber formed by the shell the eggs are laid,
the male immediately after mounting guard over them till they hatch, which
they do in about nine days.
[Illustration: _Photo by Reinhold Thiele & Co._] [_Chancery Lane, W.C._
LUMP-SUCKER.
Known also as the Cock and Hen Paddle.]
Another species, the PELLUCID GOBY, is remarkable in that its whole life's
course is run in a single year. In June and July the eggs are laid; they
are hatched in August; by the time winter has arrived the fish have reached
maturity, and die off in the following July and August, so that in
September only the fry are to be met with.
One of the strangest of all fishes is a member of the Goby Family. This is
the WALKING-FISH, so called from its habit of spending most of its time on
the mud-banks of rivers, or on the roots of trees growing in the
neighbourhood. The late Surgeon-General Day, describing these fishes as he
saw them along the side of the Burmese rivers, writes that at first sight
they look like large tadpoles. When suddenly startled by something, away
they go with a hop, skip, and a jump inland among the trees, or on the
water like a flat stone or piece of slate sent skimming by a schoolboy.
When climbing, the breast-fins are used, as if they were arms, to grasp the
boughs. If placed in deep water, these fishes are speedily drowned!
The BLENNIES are fishes whose skins are soft, slimy, and quite scaleless,
or at most covered with very tiny and degenerate scales. The general form
of the body may be seen in the photograph below. They are shore-fishes,
lurking about in the crevices of rocks, among seaweed, or under stones, and
occurring generally along the coasts of temperate and tropical regions. The
species known as the SEA-CAT or WOLF-FISH is, however, a deep-water form.
As a rule the eggs are deposited in hollow places between stones or rocks;
but in the BUTTER-FISH, or GUNNEL, the eggs are adhesive, and the parents
roll them into a ball by coiling their bodies round them. Furthermore,
since the parents are frequently found, under natural conditions, coiled
round these masses of spawn, it appears that they adopt this method of
guarding their treasures. Some species bring forth their young alive.
The largest of the family is the WOLF-FISH, whose jaws are armed with very
powerful teeth, able to crush the hardest shells, such as those of the
whelk. Sea-urchins and crabs are also eaten.
We pass on to a group comprising three families--the BARRACUDAS,
SAND-SMELTS, and GREY MULLETS.
It should be mentioned that two very distinct fishes are known as
BARRACUDAS, one of which we have already described under the name of Snoek.
The forms described here as barracudas are large, voracious fishes living
in tropical and sub-tropical seas, and evincing a preference for the coast
rather than the open sea. Attaining a length of 8 feet and a weight of 40
lbs., they are a source of danger to bathers. They are very frequently used
as food, though in the West Indies such food is attended with some danger,
as the flesh is often poisonous, from the fish having fed on smaller
poisonous fishes.
[Illustration: _Photo by Reinhold Thiele & Co._] [_Chancery Lane, W.C._
BLENNY.
Blennies have soft, shiny, scaleless skins.]
The SAND-SMELTS are small carnivorous species inhabiting the seas of
temperate and tropical regions. Many enter fresh-water, and some have
become entirely acclimatised there. Some species bear a very close
resemblance to the true smelt, from which, however, they may be readily
distinguished by their small, spinous, first back-fin. The young of at
least one small group or genus of this family are remarkable for their
habit of clinging together for some time after they are hatched in dense
masses and almost incredible numbers.
The GREY MULLETS are brackish-water fishes, feeding on vegetable growths
and minute shell-fish. They also suck up large quantities of sand into the
mouth for the sake of the minute organisms contained therein; much of this
is passed on into the stomach, which is thick and muscular, like that of
many birds. Altogether some seventy species of grey mullets are known, the
majority of which attain a weight of about 4 lbs., but there are many which
grow to 10 or 12 lbs. All are eaten, and some highly esteemed.
The FLUTE-MOUTHS, STICKLEBACKS, and TORTOISE-FISHES are three closely
allied and extremely interesting families. The first are really gigantic
marine sticklebacks, in which the jaws are produced into a long tube. They
are shore-fishes, entering brackish water, and confined to sub-tropical and
tropical parts of the Atlantic and Indo-Pacific.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
NORTHERN MULLET.
A member of the family of Grey Mullets.]
[Illustration: _Photo by Reinhold Thiele & Co._] [_Chancery Lane, W.C._
RED MULLET.
Not related to the Grey Mullets, this species is placed here for the sake
of contrast.]
Of the STICKLEBACKS there are several species, some of which are entirely
salt-water fishes, whilst others enjoy the rather unusual distinction of
being able to live in either fresh or salt water, even when rapidly
transferred from one to the other. The small species commonly inhabiting
ponds and ditches can sustain changes of this kind with impunity. These
last are very ferocious. One kept in an aquarium devoured in five hours
seventy-four young dace about a quarter of an inch long. They occasionally
occur in vast shoals, and, according to the naturalist Pennant, appear in
the river Welland, in Lincolnshire, once in seven years in amazing shoals,
so that a man employed in collecting them earned four shillings a day by
selling them at the rate of a halfpenny a bushel!
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
GARPIKES.
Frequently called Guard-fishes.]
The salt-water species, or FIFTEEN-SPINED STICKLEBACK, is less well known.
Like its fresh-water relative, it is a nest-builder, and the male defends
the eggs and young with great courage.
The TORTOISE-FISHES may serve as the representatives of the last family of
this group. They are very remarkable fishes, being invested in a wonderful
bony cuirass, formed by a modification of the skeleton, similar to what has
taken place among the Tortoises and Turtles. The body is so thin that it
looks as if it had been artificially compressed, and is semi-transparent.
Three species are known from the tropical Indo-Pacific and three from other
seas; besides these are four smaller and less perfectly armed forms, one of
which, the TRUMPET-FISH, or BELLOWS-FISH, occurs rarely off the south coast
of England.
THE GARPIKE and FLYING-FISHES are both interesting, especially the latter.
The garpike is represented by several species, easily recognised by the
long, pointed jaws. These fishes are furthermore peculiar in that the bones
are green, a colour which remains even after cooking, and on this account
some object to eating them, supposing the unusual colour to indicate
unsoundness. The elongated jaws are not developed in the young fish, and,
strangely enough, as this character is acquired, the lower jaw grows faster
than the upper. In some species the lower jaw remains permanently the
longer; hence they are known as HALF-BEAKS.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
PIPE-FISH.
The Flute-mouth, as this fish is often called, is really a gigantic
stickleback.]
The FLYING-FISHES, or FLYING-HERRINGS, like the Flying-gurnards already
noticed, are enabled, by reason of the great development of the
breast-fins, to take extended journeys through the air. The flight of these
fishes is, however, not quite the same as true flight, inasmuch as the fins
serve mainly as a parachute, and do not, by sustained vigorous movements,
propel the body through the air, like the wings of bats and birds. Darting
out of the water when pursued by an enemy or frightened by a passing
vessel, these fish are borne along by the wind, the speed at first being
very considerable, exceeding indeed that of a ship going ten miles an hour.
At a single flight they may cover as much as 500 feet, but are quite unable
to steer themselves, except when, during their course, the tail-fin is
immersed in the water, when by a stroke from one side to the other the
direction may be changed from left to right, or _vice versâ_, as the case
may be. By day they will avoid ships, but by night, when they are unable to
see, "they frequently fly," writes Dr. Günther, "against the weather-board,
where they are caught by the current of air and carried upwards to a height
of 20 feet above the surface of the water, while under ordinary
circumstances they keep close to it."
[Illustration: _Photo by A. S. Rudland & Sons._
FLYING-FISH.
More than forty distinct species of this family are known.]
----
CHAPTER VI.
_THE WRASSE-LIKE FISHES._
BY W. P. PYCRAFT, A.L.S. F.Z.S.
The members of the four families noticed in this chapter are remarkable for
their wonderful coloration. The species of the first family, from their
peculiarly striking resemblance to the Scaly-finned group, share with them
the name of CORAL-FISHES. This resemblance is a very remarkable one.
Occurring, like the Scaly-fins, more abundantly in the neighbourhood of
coral-reefs, they also resemble the latter not only in shape, but also in
coloration, the same pattern being often common to members of both
families.
To this family belongs the remarkable fish known as the AMPHIPRION, which
makes its home in the interior of an enormous species of sea-anemone
measuring 2 feet across. When first discovered by Mr. Saville-Kent, it was
believed that the fish had been swallowed--a view, however, which was
speedily rejected, when it was found that, if ejected by means of a stick,
it invariably returned. Thus the anemone is obviously to be regarded as
host, and not as captor. More than this, from the facts so far to hand, it
appears that this strangely assorted pair are mutually dependent on one
another, at least to a large extent--the fish undertaking to supply the
larder, whilst the anemone in return affords shelter from enemies. The part
played by each is as follows:--The fish, which is very conspicuous, wearing
a livery of vermilion crossed by three bands of white, sallies forth and
swims about till it attracts the attention of some other carnivorous member
of its class, on which, if it gives chase, the amphiprion returns with all
speed to its living cave, and quickly disappears down its mouth. The
pursuer, blundering against the outspread tentacles, is immediately
paralysed by a shower of stinging-darts which proceed therefrom as a result
of the shock, and, rendered insensible, becomes the spoil of both. Thus the
active fish plays the part of a lure, and in return is afforded shelter.
[Illustration: _Photo by Reinhold Thiele & Co._] [_Chancery Lane, W.C._
SPOTTED WRASSE.
On account of their greatly thickened lips wrasses are also known as
Lip-fishes.]
The WRASSES proper may be distinguished, amongst other things, by their
thickened lips--hence the name Lip-fishes given them by German
naturalists--by the greatly extended back-fin, the greater part of which is
spinous, and the arrangement of the teeth, which need not be discussed
here. They are shore-fishes, living in the neighbourhood of weed-covered
rocks, or in tropical seas, where they are most abundant, amid coral-reefs.
Most are brilliantly, many gaudily coloured, iridescent hues frequently
adding to the beauty formed by the permanent deposit of coloured pigments
in the scales. Some grow to a large size, specimens not seldom exceeding a
weight of 50 lbs., and these are the most esteemed as food-fishes, the
smaller species, as a rule, being regarded as of inferior quality.
A well-known British species is the STRIPED or RED WRASSE, the sexes of
which exhibit a remarkable variation in colour, the male having the body
marked with blue streaks or a blackish band, whilst the female has two or
three large black blotches across the tail. A second British species, the
BALLAN WRASSE, is bluish green in colour, with the scales and fin-rays
reddish orange. It may be found hiding in the deep gullies among rocks,
sheltering in the dense clusters of seaweed, and feeding on crabs and
shrimps. It takes a bait freely, and fishermen have remarked that at first
they catch few but large fish; some days later a great number may be
caught, but all will be of small size, indicating that the larger fish
assume the dominion of a district and keep the smaller at bay.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
SATIN PARROT-FISH.
The Parrot-fishes, or Parrot-wrasses, are so called on account of the
peculiar structure of the teeth in the front of the jaws, which form a
sharp-edged beak.]
Amongst the most brilliantly coloured of the wrasses are the PARROT-FISH.
Mr. Saville-Kent, writing of the species which inhabit the waters of the
Great Barrier Reef of Australia, remarks that to stand up to your knees or
higher in water, with such a shoal of magnificent fishes swimming round
you, is an experience well worth a journey to the tropics. The coloration
of these fishes, which is extremely transient, fading almost immediately
after death, nearly defies description. One of the most beautiful is
perhaps the GOLD-FINNED CORAL-FISH, in which the body is of an intense
ultramarine, whilst the fins are bright golden. Others have the most
amazing combinations of green, vermilion, blue, and yellow, in endless
variety. It was one of the parrot-fishes which found such favour with the
ancients. "In the time of Pliny," writes Dr. Günther, "it was considered to
be the first of fishes ... and the expense incurred by Elipentius was
justified, in the opinion of the Roman gourmands, by the extreme delicacy
of the flesh. It was a fish, said the poet, whose very excrement the gods
themselves were unwilling to reject. Its flesh was tender, agreeable,
sweet, easy of digestion, and quickly assimilated; yet, if it happened to
have eaten an aplysia, it produced violent diarrhoea." To this day the
Greeks hold it in high regard, and eat it with sauce made of its liver and
intestines. It feeds on seaweed, and from its habit of thoroughly chewing
its food, and moving it backwards and forwards in the mouth, it was at one
time believed that this fish chewed the cud after the fashion of the
ruminating mammals!
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
BLACK-SPOTTED PARROT-FISH.
The flesh of some of the Parrot-wrasses is of great delicacy.]
One of the most interesting of all the wrasses is a small species from King
George's Sound, which, while retaining the principal characters common to
the group, has assumed the general shape and proportions of the pipe-fish.
The third family of the wrasses are remarkable chiefly on account of the
fact that they produce their young alive. These fishes are confined to the
temperate regions of the North Pacific.
The CHROMIDS constitute the last family of the wrasse-like group. Numerous
in species, they are all dwellers in fresh-water. One species occurs in
amazing numbers in the Lake of Galilee, shoals over an acre in extent, and
so closely packed that movement seemed almost impossible, having been
recorded. They are taken in such enormous numbers that the nets in which
they are caught often break. Occasionally shoals are carried down the
Jordan into the Dead Sea; but the fish never get farther than a few yards,
becoming stupefied almost at once, and, turning over on their backs, fall
an easy prey to flocks of cormorants and kingfishers. Heaps of putrefying
carcases are washed ashore, poisoning the atmosphere, in spite of the
presence of flocks of ravens and vultures which have gathered to the feast.
[Illustration: _Photo by H. V. Letkmann_] [_New York._
A WRASSE.
The majority of the Wrasses are brilliantly coloured.]
Another species is remarkable for its peculiar method of protecting the
eggs and young. The female deposits the eggs, over 200 in number, in a
small hole worked out among the roots of reeds and rushes. There they are
taken into the mouth of the male one by one, and retained till hatched a
few days later. The young fry remain in this nursery for some considerable
time, increasing rapidly in size, so that the father-nurse is unable to
close his mouth. Some of the young develop among the gills; others lie,
closely packed, with their heads turned towards the mouth of the parent,
remaining in this position till nearly 4 inches long, when they are ejected
or wriggle out to forage for themselves.
----
CHAPTER VII.
_PIPE-FISHES, SEA-HORSES, GLOBE-FISHES, SUN-FISHES, AND THEIR ALLIES._
BY W. P. PYCRAFT, F.L.S., F.Z.S.
The fishes described in the present chapter form two well-marked groups,
known as the TUFT-GILLED and the COMB-GILLED FISHES, on account of the
peculiar arrangement of the gills, or breathing-organs; they are also
remarkable for their peculiar shapes. The breast-fins are present in all;
but in three of the families the second pair of fins, corresponding to the
hind limbs of the higher animals, are wanting.
[Illustration: _Photo by A. S. Rudland & Sons._
GLOBE-FISH.
From the formidable armature of spines, known also as the Sea-hedgehog.]
The TUFT-GILLED FISHES are represented by two families--the MAILED
TUBE-MOUTHS and the PIPE-FISHES and SEA-HORSES, all of which have undergone
very considerable modification of form, the body being encased in mail-like
armour, whilst the jaws are toothless and produced into a long tube.
The first family is composed of a few small fishes from the Indian Ocean.
Grotesque in appearance, they are remarkable also for the fact that the
female takes sole charge not only of the eggs, which are exceedingly
minute, but the young fry also. Only one other fish is known in which the
care of the eggs and young is undertaken by the female: this is one of the
Cat-fishes, described in a later chapter. The eggs in the TUBE-MOUTHS are
carried in a pouch formed by the union of the inner borders of the ventral
fins, which are long and broad. For the retention of the eggs within the
pouch its wall develops long filaments, which serve the purpose of slender
fingers.
The second of these families contains the PIPE-FISHES and SEA-HORSES. They
are small marine fishes, inhabiting the seas of tropical and temperate
regions wherever there is sufficient vegetation to offer shelter, for they
are peculiarly defenceless creatures. They possess but feeble powers of
swimming, and consequently are not seldom borne away by strong currents far
out to sea or on to distant shores. Their method of locomotion is, indeed,
quite different from that of other fishes, as they progress neither by
undulatory motions of the body nor by powerful strokes of the tail, but by
wriggling in the case of the pipe-fishes, or vibrating motions of the
back-fin in the sea-horses.
The long, semi-cylindrical PIPE-FISHES, partly on account of their peculiar
form and colour, and partly on account of their swaying motions, so closely
resemble the fronds of seaweed amongst which they dwell as to pass
unnoticed by their enemies. Unlike the Tube-mouths, just described, the
care of the eggs and young devolves upon the males. The young are borne in
a pouch, but, ventral fins being wanting, this is formed by a fold of skin
developed from each side of the trunk and tail, the free margins being
united in the middle line. Here the eggs remain till they are hatched. But
the pouch is by no means done with after this event, for the young continue
to occupy it for some time, returning when danger threatens--a habit which
recalls the custom of the young of the kangaroo. Mr. Yarrell relates a
curious fact which he gleaned from some fishermen--to wit, that if they
take a pipe-fish, open the pouch, and drop the young into the sea, they
will not disperse, but hover around the spot, as if waiting for their
parent. Then, if the newly opened fish be held in the water, the young
immediately return and enter the pouch. In another species of pipe-fish the
eggs, instead of being carried in a pouch, are held by a sticky secretion
to a groove in the under surface of the parent. This groove would seem to
indicate the beginning from which the complete pouch has been developed.
The pipe-fishes swim in a very peculiar manner, holding the body now in a
vertical, and now in a horizontal position, accompanied by contortions of
every conceivable kind, poking their long snouts into bunches of seaweed in
search of food as they go.
[Illustration: _Photo by A. S. Rudland & Sons._
BLACK-SPOTTED GLOBE-FISH.
Globe-fishes possess the power of inflating the body with air, when they
float at the surface, and thus escape enemies.]
[Illustration: _Photo by N. Lazarnick_] [_New York._
TRIGGER-FISH.
A well-known member of the File-fishes.]
The SEA-HORSES have a still more eccentrically modified form, inasmuch as
the body is thrown into a series of curves, the head being bent upon the
trunk in a manner suggestive of the head and neck of the horse; hence the
name of the group. The tail, which lacks the membranous portion, or fin,
can be spirally coiled, and is used as an organ of prehension, and on this
account is unique amongst fishes. Gripping the stems of seaweeds with this
tail, and swaying the body to and fro among the vegetation, the fish is
rendered comparatively inconspicuous, the lines of the body being broken up
by numerous more or less filamentous processes, which in one species, the
FUCUS-LIKE SEA-HORSE, become excessively developed, forming long,
frond-like blades. These, streaming in the water, both by their shape and
coloration render the resemblance to the vegetable growths in which the
animal hides so perfect that detection is almost impossible. Thus they
furnish one of the most remarkable examples of adaptation to the
environment amongst living animals. The males of most sea-horses, like the
pipe-fishes, carry the eggs and young in a pouch on the abdomen, but in the
species just mentioned the eggs are embedded in the soft skin on the under
surface of the tail.
Sea-horses swim with the body more or less vertical, the motive power being
supplied by rapid vibration of the back-fin. Both pipe-fishes and
sea-horses occur in British seas, the first being the more common.
[Illustration: _Photo by H. V. Letkmann_] [_New York._
COFFER-FISHES.
Coffer-fishes have the body encased in a hard shell of closely fitting
plates, leaving only the tail and fins free to move.]
The COMB-GILLED FISHES, to which we come next, are divided into two
families, whose members are as remarkable for their extraordinary shape as
are the tuft-gilled forms just discussed. The abnormal shapes which mark
out certain fishes so conspicuously from the more normal and typical forms
are generally regarded as adaptations, serving to ensure concealment, to
ward off attack, or to effect the capture of prey otherwise unattainable.
Instances illustrating all three of these ends are furnished by these two
groups of the tuft- and comb-gilled fishes.
The FILE-FISHES and COFFER-FISHES, which form the first of the two
families, present considerable variation in shape as well as in the
covering of the body, which may be naked, covered with rough scales or bony
spines, or invested in a complete bony cuirass.
The file-fishes are represented by numerous species, the typical one being
known also as the TRIGGER-FISH, on account of an armature of spines on the
top of the back. These spines are three in number; the first is very
strong, roughened like a file--hence the name File-fish--and hollowed out
behind to receive the second much smaller spine, which has a projection in
front at its base, fitting into a notch in the first. Thus these two spines
can only be raised or depressed simultaneously, and the first cannot be
forced down unless the second has been previously depressed. These fishes
have very powerful teeth, to break off pieces of coral, which form a large
part of their diet. They also destroy a large number of shell-fish, and
work great destruction amongst pearl-oysters. Frequently these fishes, when
eaten, prove highly poisonous, from having fed on poisonous corals,
jelly-fish, or decomposing substances.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
LACE-FINNED LEATHER-JACKET.
Another species of File-fish.]
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
SPOTTED BOX- OR TRUNK-FISH.
In this species of Coffer-fish the arrangement of the plates forming the
hard cuirass can be plainly seen.]
As a rule file-fishes are of small size, but some attain a length of 2
feet, and many are beautifully and symmetrically marked.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
SEA-HORSES.
The species on the right is remarkable for the development of long
leaf-like processes all over the body, causing the fish to bear a very
close resemblance to the seaweed amongst which it dwells.]
The COFFER-FISHES derive their name from the box-like cuirass in which they
are invested. This is formed by numerous closely fitting, hexagonal bony
plates, forming a mosaic, and leaving only the fins and hind part of the
tail free. This bony case varies greatly in form, in some species being
three-ridged, in others four- or even five-ridged; while in some long horns
are developed, making the defensive armature still more complex. More than
twenty species are known, all confined to tropical and sub-tropical seas.
The GLOBE-FISHES and SUN-FISHES constitute the last family of this really
extraordinary assemblage. The covering of the body consists either of
minute scales or large spines, which can frequently be raised or depressed
at will. All the members inhabit tropical or sub-tropical seas, and a few
occur in the fresh-waters of the same regions.
The GLOBE-FISHES have short, thick bodies, covered either with small
spines, as in the TOAD-FISH, or very large ones, as in the PORCUPINE-FISH,
or SEA-HEDGEHOG. They are remarkable for their habit of filling the gullet
with air, and then distending the body to an enormous size. This device
enables the fish to escape its enemies; for when so inflated it rises to
the surface and floats belly-upwards, and, the inflated portion projecting
above the water, the fish is blown along by the wind to more secure
regions. The more heavily armed species become still more formidable when
inflated, as the spines are then fully erected. Escaping from enemies below
by flight, they are thus secure from enemies above by reason of their
armature. Globe-fishes have been found floating alive and unhurt within the
stomachs of sharks which had swallowed them, and one has even been known to
eat its way out through its captor's side, and so killing its would-be
devourer! When a globe-fish desires to return to its normal elongated
shape, it expels the air from the gullet through the mouth and gills, the
expulsion causing a curious hissing sound.
Extremely unlike the foregoing members of the group of comb-gilled fishes,
the SUN-FISH is nevertheless quite as remarkable in form, looking as if it
had undergone the amputation of its hind parts. The singular shape of the
other members of the comb- and tuft-gilled fishes are undoubtedly
adaptations to avoid enemies, either by rendering the animal inconspicuous,
or hurtful by reason of its powerful armature. The form of the sun-fish
appears to be an adaptation for the capture of food, as this fish preys
largely upon the fry of other fishes which inhabit enormous depths, and
consequently can only be obtained by diving. Sun-fishes inhabit the
surface-waters, but as divers have few equals.
[Illustration: _Photo by W. Saville-Kent_, F.Z.S.] [_Milford-on-Sea._
SEA-HORSES.
Attaching themselves to marine plants by twisting their tails around them.]
[Illustration: _Photo by Dr. Robert T. Morris, New York._ _Printed at
Lyons, France._
A SALMON LEAPING.
The height to which salmon will leap in ascending a waterfall is little
short of marvellous. When the fall is very high the ascent is often
accomplished in a series of leaps, the fish resting in pools of
comparatively still water.]
----
CHAPTER VIII.
_THE COD FAMILY._
BY JOHN BICKERDYKE, M.A.
The large and important Cod Family belongs to the order of Spineless Fishes
and the group in which both sides of the head are symmetrical. The Common
Cod, the Whiting, the Haddock, the Pollack, the Coal-fish, the Hake, the
Ling, and the little Rocklings, all belong to this important family, which
has one representative in fresh-water, the Burbot, or Eel-pout, found in
various rivers in Central and Northern Europe and North America.
Perhaps the most remarkable member of the Cod Family is the CHIASMODUS,
which has huge jaws lined with large pointed teeth, and a distensible
stomach and abdomen. During the _Challenger_ Expedition a specimen was
taken 1,500 fathoms down in the North Atlantic. It had swallowed another
fish, a kind of scopelus, more than twice its own size. The stomach of the
chiasmodus had swelled to an enormous extent, and had become so thin from
distension that the fish inside could be clearly seen through its walls.
The scopelus, it is interesting to mention, is a fish brought up sometimes
by the dredge from 2,500 fathoms. It occasionally comes to the surface at
night, and has phosphorescent spots along its sides, giving out a dim
light, which has its uses in the dark depths of the sea.
To come back to the head of the family, the COD is a fairly plentiful fish
all around the British and Irish coasts, but appears to be decreasing in
some waters as time goes on, owing to the over-trawling of the North Sea.
Off the coasts of Norway, in the neighbourhood of the Lofoden Islands, the
cod are sometimes so thickly packed in shoals that as the fishermen lower
their tackle they can feel the leads hitting the backs of the fishes. Both
there and off the Faröe Islands and Iceland it is common practice to fish
with a hook bearing a little piece of polished lead on its shank, no other
bait being required, owing to the cod being so numerous that food is
scarce.
[Illustration: _Photo by A. S. Rudland & Sons._
WHITING.
Easily distinguished from the cod by the absence of a barbel on the chin.]
About the commencement of the fifteenth century the English began to go to
Iceland for cod, and since the sixteenth century English cod-fishing
vessels have visited Newfoundland and other far northern waters, which
produce fish superior to English cod. It should be mentioned that the Cod
Family is not found to any extent in tropical seas.
While the BURBOT is one of the few species of the group inhabiting
fresh-water, and is peculiar in living there permanently, there are
instances recorded of POLLACK having ascended from the salt water of the
Norwegian fjords into fresh-water lakes, and it is an undoubted fact that
many other species of sea-fish can accustom themselves to a residence in
fresh-water.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
POLLACK-WHITING.
A British representative of the group in which the lower jaw is the longer
and all the teeth of the upper jaw are of equal size.]
All through the year cod frequent the British coasts; but it is two or
three months before the spawning-season, which commences in January or
later according to the locality, that they gather in vast shoals and come
close inshore. First come the small codling of a pound or so, and as the
winter approaches the longshore fish are found gradually to increase in
size, until by Christmas-time it is no uncommon thing on the east coast of
England and Scotland for fish of from 10 to 20 lbs. to be caught from the
beach.
As a rule the eggs of cod float, owing to a little globule of oil which
each one contains, but in water which lacks salinity they sink. The
quantities of eggs shed by each fish are enormous; nearly two millions were
counted in a cod of a little under 12 lbs. It is fairly certain, however,
that not more than two or three, if so many, mature fish are the product of
the two million eggs; for if each fish even doubled itself in numbers (if
we may use the expression) every year, the sea would soon contain more fish
than water. Millions upon millions of eggs are destroyed when there is an
on-shore wind during the spawning-season. Sometimes the shore on which they
have been wafted has been seen to glisten with them.
By the end of summer such of the young cod-fish as have escaped their many
dangers attain about 1 inch in length. They are very varied in colour,
which depends on that of the seaweed and their other surroundings. The
parent fish, too, vary somewhat in appearance, those round the English
coast as a rule having brown backs with irregular spotty markings on the
sides, while those from more northern waters usually have darker backs and
are less often spotted. Cod are most enormous feeders, and in consequence
grow very rapidly. At the Southport Aquarium codling of only ¾ lb.
increased in weight to 6 or 7 lbs. in about sixteen months.
So voracious is the cod that it is very apt to swallow anything it sees
moving, without considering whether it is wholesome. In 1879 a black
guillemot in perfect condition was removed from the stomach of one of these
fish; while among other strange finds by cod-fishermen from the same
receptacle was a piece of tallow candle 7 inches long, a hare, a partridge,
a white turnip, and, going back to the year 1626, a "work in three
treatises," which was found in the stomach of a fish captured in Lynn Deeps
on midsummer eve, and brought to the Vice-Chancellor of Cambridge. The
usual food of cod is, however, small fish of various kinds--herrings,
pilchards, sprats, crabs, and sea-worms; but the species is not particular
what it seizes when shoaling before the spawning-season and food is scarce
owing to the number of mouths.
----
CHAPTER IX.
_CAVE-FISHES, SAND-EELS AND THEIR ALLIES, AND FLAT-FISHES._
BY W. P. PYCRAFT, A.L.S., F.Z.S.
The subterranean fresh-water caves of Cuba furnish the most interesting and
most remarkable members of the family in certain small fishes known as
CAVE-FISHES. Living in complete darkness, the eyes have degenerated so as
to be no longer useful as organs of sight; indeed, in many species they are
entirely wanting. By way of compensation delicate organs of touch have been
developed, taking the form, in different species, of barbels, hair-like
processes, or tubercles. These blind fishes are closely allied to certain
marine forms found in the tropical Atlantic and Indian Oceans, and it is
curious to note that amongst these about seven very rare species are found
at great depths in the southern oceans, so great that light fails to reach
them, and they too are blind.
The SAND-EELS, or LAUNCES, are extremely common on the sandy shores of
Europe and North America, living in vast shoals, and displaying a wonderful
unison in their movements, rising and falling as with one accord. They
burrow in the sand with amazing rapidity, forcing their way by means of a
horny projection on the lower jaw, and remaining buried at ebb-tide some 5
or 6 inches under the sand, when they are captured by fishermen, armed with
rakes, for bait. When swimming in shoals, their presence is often betrayed
by schools of porpoises, which feed greedily upon them, preventing their
return to the bottom by getting under the shoal, whilst others swim round
it. Mackerel also make large raids upon the ranks of such shoals.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
SPOTTED SOLE.
A larger and coarser fish than the common sole.]
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
HALIBUT.
The largest member of the Flat-fish Family. The back-fin usually commences
much farther forward.]
FLAT-FISHES may be reckoned among the most important of food-fishes, and
besides are of quite peculiar interest, on account of the remarkable
modifications of structure which they have undergone. They differ from all
other vertebrates in that, save for the first few weeks of existence, they
spend the whole of their lives with one side of the body uppermost--the
right or left, according to the species. Whether resting or swimming, this
position holds good. The newly hatched fish, however, maintains the normal
poise of the body, the back being uppermost. Of the many changes which the
organs of the body undergo during this strange transformation from a
"round" to a "flat" fish, one of the most interesting is that which
concerns the eyes. These, in the very young fish, lie one on either side of
the head; but as the fish grows older it begins to lie on its side on the
ground, and ultimately, when it is two or three months old, loses the power
of sustaining itself in an upright position altogether. The most remarkable
feature in this very strange mode of development is, that as the fish comes
to lie more and more on its side, so the eye which is undermost begins to
move round to the other side, till eventually the two eyes lie side by side
on the upper-surface. Strangely enough, in some species the eye moves
_round_ the head, passing over its edge, and so to its place beside the
stationary eye, whilst in others it acquires its ultimate position by
moving _through_ the head, sinking in on one side and appearing again on
the other. The coloration of these fishes is also peculiar, in that the two
sides are quite differently coloured, the upper side resembling in tone
that of the sea-bottom, whilst the under side is pure white. In the young
fish, before the habit of lying on one side has been acquired, both sides
are coloured alike. The difference in coloration between the two sides of
the adult fish appears to be due to the effect of light, since in
flat-fishes kept in a tank with a mirror at the bottom the under-surface
was found in many cases to be very largely coloured. But the colour of the
upper-surface is by no means constant. On the contrary, the flat-fish
appears to possess the power, in common with all other fishes, of changing
its colour so as to harmonise with the tone of its surroundings. Thus on a
light sandy ground the exposed surface of the body becomes pale, while on a
dark muddy bottom it is almost black. By this power of changing the colour
of the exposed portion of the body so as to harmonise with the
surroundings, the fish is enabled to become in a large measure invisible,
and in proportion to the effectiveness of the change to escape its enemies.
Some soles are quite invisible.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
BRILL.
As in the turbot, the eyes are on the left side of the head, instead of on
the right side, as in the halibut.]
The most important of the flat-fishes are the PLAICE, FLOUNDER, DAB,
HALIBUT, SOLE, TURBOT, and BRILL.
The PLAICE is one of the commonest of the British flat-fishes, and may be
distinguished by the numerous orange or red spots which are scattered over
the upper surface of the body. From 15 to 18 inches in length, specimens
are occasionally captured which have attained a length of 28 inches. Plaice
feed on shell-fish, such as mussels or scallops, which they crush by means
of strong, blunt teeth in the throat; but worms are also eaten.
The eggs of the plaice are amongst the largest fish-eggs known.
The FLOUNDER is a smaller fish than the plaice, and lacks the red spots. It
differs from the other flat-fishes in the preference it shows for the
mouths of rivers, ascending these, indeed, so far as to enter fresh-water.
The HALIBUT is the largest of the flat-fishes, specimens of as much as 20
feet in length being on record, while examples of from 6 to 7 feet long are
not uncommon in Grimsby market. This fish has a wide distribution,
occurring on both sides of the North Atlantic and North Pacific, being most
abundant in deep water. The halibut which are brought into the markets of
Grimsby and Hull are chiefly caught off the coasts of Iceland and the
Faröes with long lines.
The SOLE is a shallow-water fish, feeding chiefly upon worms, crabs, and
shrimps. These it apparently hunts by smell, gliding over the sea-bottom,
and tapping with the lower side of its head, which is provided with
sensitive organs of touch in the shape of filaments. By day it conceals
itself by burrowing in the sand, coming out after dark to feed.
The TURBOT resembles the brill, from which it may be distinguished by the
greater breadth of the body in proportion to the length, the absence of
scales, and the presence of large bony tubercles scattered over the
surface. In Great Britain the turbot is most abundant in the English
Channel.
The BRILL closely resembles the turbot not only in general form, but in the
numerical superiority of the females, and in the habits of the young,
which, like the turbot, are surface-feeders and possess an air-bladder.
----
CHAPTER X.
_EELS AND CAT-FISHES._
BY W. P. PYCRAFT, A.L.S., F.Z.S.
Eels, like flat-fishes, show plainly, in the shape of their bodies, a
remarkably perfect adaptation to their environment. They are burrowing
fishes, passing much of their time buried in the mud, and leaving little
more than the head exposed. In accordance with this habit, the body is very
long and round, and lacks both the hinder paired fins, and scales. When
swimming, the body is propelled by rapid undulations, the movement being
from side to side, it may be remarked, instead of up and down, as in the
"serpentine" movements of snakes.
Whether all the fishes commonly regarded as eels really belong to this
family or not is a moot-point. It is possible that the eel shape has been
independently acquired by unrelated forms as a result of adaptation to a
similar mode of life. But as the group now stands it embraces several
distinct types,--the COMMON FRESH-WATER EELS; numerous marine species, such
as CONGERS, SERPENT-EELS, DEEP-SEA EELS, and PAINTED EELS; and the
fresh-water ELECTRIC EELS.
[Illustration: _Photo by N. Lazarnick_] [_New York._
EELS.
Two species are shown in this photograph.]
The RIVER-EELS and CONGERS are perhaps the best known, and are also highly
important food-fishes. That they are fishes of comparatively slow growth
seems to be shown by the fact that the common eel takes about four or five
years to attain a weight of between 5 and 6 lbs. The males are smaller than
the females, the greatest length attained by the former being a little over
1 foot 7 inches, whilst the latter may attain a length of nearly 4 feet.
For a long while what is now known to be the female river-eel was regarded
as a distinct species--the SHARP-NOSED EEL. The two sexes have quite
different habits, the smaller males being found mostly in the brackish
water of river-mouths, and rarely above the reach of the tides, whilst the
females ascend the rivers for great distances, thousands finding their way
into isolated ponds, which they reach by travelling overland. Here they
appear to remain till they have reached maturity, when they migrate with
one accord to the sea. Coming down the rivers during the months of October
and November, hundreds are taken in large niches with traps, the mouths of
which are directed up-stream.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
CONGER-EEL.
The females of this species often swallow the males.]
The migration of eels to the sea is for the sole purpose of spawning and
fertilising the eggs, which done, they die. The spawning appears to take
place in extremely deep water, where the young eels pass the earlier stages
of their development. Like the majority of young fishes, the fry are at
first very different in form from the adults, and many have from time to
time been described as distinct species, no suspicion of their true nature
having been aroused. And this is not to be wondered at, for at this stage
they are perfectly transparent and compressed from side to side, so as to
be but little thicker than a sheet of stout paper; the head is ridiculously
small, and only median fins are present. As development proceeds, having
reached a certain maximum size, they, strangely enough, begin to slowly
diminish, growing shorter and at the same time rounder, so that eventually,
by the time the characteristic eel form is attained, they are considerably
shorter than they were at the maximum period of larval life.
By the time the adult eel form has been attained, the larvæ have made their
way to the mouths of various rivers, preparatory to making their ascent,
which takes place between February and May. They are then from 2 to 5
inches long, and perfectly transparent save for a black line inside the
body, running along the spinal cord. The numbers passing up a single river
during this ascent are almost beyond belief. In one of these migrations, or
"eel-fares," upwards of three tons were captured in a single day in the
Gloucester district in 1886, and it has been calculated that more than
14,000 go to make a pound weight. In the previous year the annual
consumption of eels was estimated at a minimum of 1,650 tons, with a total
value of £130,000. Few obstacles seem too great to be overcome in their
ascent, for they will ascend the flood-gates of locks, or even travel
overland if the ground be wet, till a desirable resting-place is found. In
some parts of England these young eels, or "elvers," as they are called,
are salted and made into cakes.
The CONGER-EEL is a marine species, differing from the river-eel, amongst
other things, in its larger head and eyes, and in the arrangement of its
teeth and the large size of the gill-openings. The conger is also greatly
superior in size, examples of between 6 and 7 feet in length and 60 lbs. in
weight being common. The females are larger than the males, and an instance
is on record of a female which was over 8 feet in length and weighed 128
lbs. Congers feed on other fishes, cuttle-fishes, and lobsters, as well as
upon one another, the larger females eating the smaller males.
[Illustration: _Photo by Dr. R. W. Shufeldt_] [_Washington._
CAT-FISH.
Note the presence of barbels, or "feelers," round the mouth]
SERPENT-EELS are confined to tropical and sub-tropical seas, and are
remarkable for their extreme voracity. More than eighty species are known,
some of which are brilliantly coloured.
The DEEP-SEA EELS are represented by numerous species, and dwell at depths
varying from 340 to 2,000 fathoms. In some species the body is remarkably
modified, the mouth being of enormous size, and the stomach capable of
marvellous distension, so much so that eels of this family have been
captured which had swallowed fishes several times their own weight. The
tail in many of the deep-sea eels tapers to a fine hair-like point.
The PAINTED EELS are remarkable for their bright spotted or mottled
coloration, and are of large size, ranging from 6 to 8 feet in length.
Armed with formidable teeth, the larger species are held in no little fear
by fishermen and bathers, attacks from these fishes being by no means rare.
Their distribution is closely similar to that of the Serpent-eels.
[Illustration: _Photo by N. Lazarnick_] [_New York._
PAINTED EELS FROM BERMUDA.
More than eighty species of these fishes are known.]
[Illustration: _Photo R. Lazarnick_] [_New York._
CAT-FISHES.
These belong to the unarmoured group.]
The ELECTRIC EEL is an extremely abundant fish in the rivers and lagoons of
Brazil and the Guianas. It is the most powerful of the electric fishes, and
attains a length of 6 feet. The electric organs of this fish are
sufficiently strong to kill by their shock other fishes and even mammals.
The traveller Humboldt is responsible for the statement, now generally
discredited, that the Indians procured this fish by driving horses into the
water, and so provoking such violent discharges from the fish that they
became exhausted and fell an easy prey.
The CAT-FISHES, or SHEATH-FISHES, are an extremely interesting group, one
of the principal characteristics of which is the total absence of scales,
the body being either entirely naked or armed with bony tubercles or
overlapping plates. Another peculiarity of these fishes is the presence of
feelers round the mouth; these, by their delicate sense of touch, enable
the fish to procure its food in extremely muddy water, when the eyes would
be useless. The latter, indeed, in many species are extremely reduced in
size. Many cat-fishes are armed with powerful spines, attached to the body
by a very complicated mechanism. Such spines are capable of inflicting
dangerous wounds, either by the introduction of poison or the violent
inflammation following on the laceration of the wounded part. Some species
have elaborate accessory breathing-organs, enabling them to travel overland
for short distances from one piece of water to another. Other members of
the group possess electrical organs of considerable power; one species
inhabiting the Nile attains a length of 4 feet.
The nesting-habits of the group are exceedingly interesting, some building
nests in which to deposit the eggs; others carry the eggs in the mouth till
they hatch. In one species the care of the eggs is undertaken by the
female, which carries them about embedded in the skin of the under surface
of the body, which at this season becomes very soft and spongy. When the
eggs are laid, she presses them into the spongy skin by lying on them.
The cat-fishes are of world-wide distribution, but only one species, the
WELS, occurs in European waters. It commonly attains a length of from 6 to
9 feet, and occasionally as much as 13 feet. The majority of cat-fishes
inhabit fresh-water, but some are marine.
----
CHAPTER XI.
_THE CARP FAMILY._
BY JOHN BICKERDYKE, M.A.
[Illustration: _Photo by A. S. Rudland & Sons._
CARP.
The members of the Carp Tribe are vegetable-feeders. They have teeth in the
throat, but none in the jaws.]
The Carp Family, like the Perch group, is one of the largest among fishes.
It includes the Rudd, Roach, Tench, Bream, Minnow, etc., and is divided
into many groups, which again include numerous species found chiefly in the
temperate and tropical parts of the world. Included among these are the
Barbels, of which there are about 200 species, varying from little fishes
of 2 inches to monsters of 6 feet or more in length. Some of the largest
are found in the Tigris; but the Mahseer of India must be regarded as the
king of all the species. In some of the rivers flowing from the Himalaya
Mountains are curious Barbel which have their vent and anal fin in a sheath
covered with large scales. Roach are important members of the Carp Family,
and the Roach group is a very large one, including the various fishes
coming under the term of "white fish" in Germany. The Roach proper is
common all over Europe north of the Alps. In this group is the Ide of the
central and northern parts of Europe, which when domesticated becomes
golden in hue, and is then called the Golden Orf, a pretty fish kept in
many English aquariums. Rudd are found all over Europe and Asia Minor. Of
Tench, only one species is known, the Golden Tench being merely a variety
differing in the matter of colour. The Bream group consists of the Common
Bream, Bream-flat, and the American Bream, or Shiner. Lastly, we may
mention the Bleak group, of which there are fifteen known species in
Europe, East Africa, and the temperate parts of Asia. This list by no means
exhausts the numerous members of the Carp Family.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
GOLD-FISH.
A native of China and the warmer parts of Japan.]
The COMMON CARP is one of the most remarkable fishes which swim. In early
times in England it was extensively cultivated as a food-fish, and in
Germany at the present day is as much domesticated as the sheep, pig, or
ox. The fish-culturists have indeed done extraordinary things with it,
having, for instance, produced a variety with a single row of scales down
each side and sometimes on the back only, called the MIRROR-CARP, or
KING-CARP. There is also the LEATHER-CARP, with no scales at all, which is
much esteemed in Germany.
There is reason to believe that the common carp was originally a native of
the East, and it certainly has been domesticated in China for many hundreds
of years. Thence it is supposed to have been imported to Germany and
Sweden, reaching England some time in the early years of the fifteenth
century. In that curious work the "Boke of St. Albans," published in 1496,
it is said that the carp is a "dayntous fysshe, but there ben fewe in
Englonde, and therefore I wryte the lesse of hym."
China is the home of the GOLD-FISH, a pretty little carp common in that
country and the warmer parts of Japan. The Chinese have distorted Nature
with regard to this fish even more than the Germans have the common carp.
Their most extraordinary monstrosity is, perhaps, the TELESCOPE-FISH, which
has a huge tail and projecting eyes. It is believed that gold-fish were not
known in England before the year 1691.
The carp has many interesting peculiarities. It is an extraordinarily
fertile fish, and one of the most rapid growers in fresh-water. Under the
most favourable conditions it attains a weight of from 3 to 3½ lbs. in
three years. In a pond which is overstocked, carp hardly increase in weight
at all; while, on the other hand, their growth in hot countries is very
much greater than above stated. A fish of from 4 to 5 lbs. may contain, on
an average, from 400,000 to 500,000 eggs; these are spawned in May or June,
and hatched in from twelve to sixteen days, according to the temperature.
The life of this curious fish may be one of extraordinary duration, carp
having been known to attain an age of a hundred years or more. When very
old, they are apt to go blind and develop white marks, due to the growth of
funguses.
In the winter carp either bury themselves in the mud, or lie among the
water-weeds or roots of trees at the bottom. They are vegetarians for the
most part, with no teeth in their mouths, but strong, powerful
grinding-teeth in their throats; they are believed to regurgitate their
food and chew it, somewhat as a cow chews the cud.
With regard to the weight which this fish attains, one of 19 lbs. was taken
at Sheffield Park in 1882. This was exceptionally large; but one still
larger, weighing 21 lbs. 10 ozs., was caught at Bayham Abbey, near
Lamberhurst, in 1870; while one of 22 lbs. was exhibited many years ago to
the Zoological Society. In the German lakes these fish reach a weight of 40
lbs., or even more.
Carp will, however, occasionally eat small fish, and have even been caught
with a salmon-fly.
----
CHAPTER XII.
_PIKES, ARAPAIMAS, BEAKED SALMON, AND SCOPELIDS._
BY W. P. PYCRAFT, A.L.S., F.Z.S.
The Pikes are strictly fresh-water fishes, which are extremely voracious,
and grow to a large size. They are met with in most of the fresh-waters of
Europe, Asia, and America; yet they must be regarded rather as a Western
than an Eastern type, since all the known species occur in America, whilst
only one--the Common Pike--is known outside that country. These fishes
capture their prey by stealth--practised, however, not so much by
concealment as by lying suspended in the water, perfectly motionless save
for the movement of the gills, which is barely perceptible. When the victim
comes within reach, it is seized by a sudden rush. The form of the body is
admirably adapted to this manner of feeding, resembling rather a submerged
log than a fish. It is, furthermore, on account of this shape that the name
Pike has been bestowed, since it recalls the "pike" borne by the soldiers
of bygone days.
When on the feed, nothing comes amiss to pike, and the havoc they commit in
trout-streams is enormous. Not only other fishes are devoured, but both the
young and adults of water-birds are frequently seized, and instances are on
record where boys have been attacked while bathing. The mouth of a pike
bristles with teeth, even the roof being thickly covered. These are all
attached by hinges, moving readily backwards towards the throat, so as to
assist the swallowing operation, but preventing any possibility of the
victim's escape.
In Great Britain the pike is held in high esteem by anglers, though as an
article of food it does not find much favour. The females are larger than
the males. The largest specimens attain a length of about 4 feet, sometimes
a little more, and a weight of from 36 to 37 lbs.
[Illustration: _Photo by Dr. R. W. Shufeldt_] [_Washington._
PIKE.
The most voracious of British fresh-water fishes.]
About six species of pike are known, five of which are confined to American
waters. Of these, the one known as the MUSKET-LUNGE, or MUSKINONGE, attains
the same large size as the common pike; the other species are known as
PIKEREL. The immature pike is commonly called a JACK.
[Illustration: _Photo by N. Lazarnick_] [_New York._
PIKEREL.
This is an American species.]
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
"SERGEANT BAKER."
An edible Australian representative of the group of fishes which, for want
of an English name, are here called Scopelids.]
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
BEAKED SALMON.
Known in New Zealand as the Sand-eel.]
The ARAPAIMAS are large fresh-water fishes, confined to the tropics, their
distribution being practically the same as that of the Lung-fishes; they
are represented in America, Australia, and Africa, but one species occurs
in the East Indian Archipelago. The largest species of all--which is also
the largest fresh-water bony fish known--is found in the rivers of Brazil
and the Guianas, attaining a length of 15 feet and a weight of 400 lbs. It
is highly esteemed as an article of food, being salted and exported from
the inland fisheries to the sea-ports. The natives take it either with a
rod and line, or with a bow and arrow, a line being fastened to the arrow,
thus converting it into a harpoon.
Four species of arapaimas are distinguished by the presence of "barbels" on
the chin; of these, two are Australian, one American, and one occurs in
Sumatra and Borneo. Yet another species is found in the Nile and the rivers
of West Africa. The Australian species, like the large Brazilian form, are
highly esteemed as food; one of these, known as the DAWSON RIVER SALMON, is
confined to the rivers of Queensland, the other to the rivers emptying into
the Gulf of Carpentaria.
The BEAKED SALMON occurs in the open seas of the Cape, Japan, and
Australia; but in New Zealand, where it is known as the SAND-EEL, it is
found in bays with a sandy bottom.
The group of fishes known as SCOPELIDS is one of particular interest, on
account of the number of remarkable forms which it contains. For the most
part they are inhabitants of the open sea, many being found only at great
depths. Of the latter, some apparently come to the surface to feed at
night, whilst others are entirely confined to the abysses of the ocean. As
with the members of other groups which have adopted a deep-sea habitat,
certain modifications of the body have become necessary in these fishes.
Many of them have a direct relation to the absence of light, which has
rendered normal eyes of little use; consequently the eyes of these fishes
have become either greatly reduced or enormously enlarged, or sometimes
lost altogether. As a rule the large-eyed forms are those which come to the
surface at night or do not live beyond the reach of daylight; whilst those
in which the eyes are small or reduced live in the very lowest depths, far
beyond the limit of daylight. In all these forms compensation for the loss
of light has taken place, generally by the development of phosphorescent
organs. These may take the form of a number of luminous areas distributed
down each side of the body, as in the PHOSPHORESCENT SARDINE; or of a pair
of lens-like light-producing organs, occupying the place of the eyes of
other fishes. Another eyeless member of the group, instead of developing
light-producing organs, has increased the length of the rays of the paired
fins to an enormous extent, so that they serve as delicate feelers either
for the discovery of food or the detection of enemies. Many of the fishes
of this group have extremely large mouths, armed with a formidable array of
tusk-like teeth, between which are numerous smaller ones.
As food-fishes the majority of the Scopelids are not of much value. The
species known as the QUEENSLAND SMELT, shown in the adjoining photograph,
is an edible species, occurring off the north-west coast of Australia. Its
near ally, the BUMMALOE, or BOMBAY DUCK, however, enjoys a quite
exceptional notoriety. Salted and dried, it is exported in large quantities
from Bombay and the coast of Malabar, and forms an indispensable adjunct to
an Indian curry. This fish apparently inhabits considerable depths, and
when freshly taken is brilliantly phosphorescent. Another edible species is
the "SERGEANT BAKER" of Australia, of which a photograph is given on page
653.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
QUEENSLAND SMELT.
A near ally of the Bummaloe, or Bombay Duck, that indispensable adjunct to
an Indian curry.]
With regard to the deep-sea Scopelids, it is interesting to note that, in
addition to very remarkable modifications of the eyes and fins, and the
production of phosphorescent light, certain of the body-cavities are
characterised by an intensely black coloration. The inside of the mouth,
the gills, and the lining of the abdomen, for example, are always so
coloured in those fishes which inhabit the deepest abysses. This coloration
is difficult to account for, but it is generally supposed to be due to
excretory products. Another interesting point concerns the air-bladder.
Whenever this organ is present in the fishes of this or any other family
inhabiting the abysses of the ocean, it bursts before the unfortunate
victim is brought to the surface, owing to the enormous differences in
pressure which obtain between the depths of the sea and the surface.
----
CHAPTER XIII.
_THE SALMON FAMILY._
BY SIR HERBERT MAXWELL, BART., F.R.S.
Although the Salmon Family occupies a low place in the classification of
fishes, yet every member thereof is possessed of singular beauty of form
and colour. The ATLANTIC SALMON, which is the species frequenting European
rivers and those of the eastern coast of North America, may be considered
the type of the family, and certainly it would be difficult to name any
animal more perfectly adapted to its peculiar mode of life, which is one of
constant activity. A native of fresh-water, hatched in early spring from
eggs laid in rivers during the winter months, it spends from fifteen to
twenty-seven months in the shallows of the river, almost indistinguishable
in habits and appearance from a small common trout. Sometimes in the second
spring after its birth, and failing that, always in the third spring, the
fish, having attained the length of 5 or 6 inches, undergoes a wonderful
change: its prevailing tints of olive and gold become overspread with a
glittering coat of silver, known to anglers as the "sea-jacket," and shoals
of "smolts," as they are called in this stage, begin descending to the sea.
In about fifteen or eighteen months, perhaps in some instances longer, they
return to the inland waters as "grilse"--small salmon from 2 to 5 lbs. in
weight. Grilse and mature salmon spawn chiefly in November and December,
undergoing, before they do so, another strange metamorphosis. Their
brilliant silvery scales become darkly discoloured, the males turning
copper-colour, the females blackish and dull purple; their elegant form
becoming distorted to such a degree as to render them hardly recognisable
as the same fish which left the tide in the perfection of beauty. In their
efforts to reach the higher waters where they spawn, salmon display
extraordinary perseverance and activity in surmounting weirs, waterfalls,
and other obstacles which bar their way. After spawning, the fish are
emaciated and lanky, but speedily regain the bright silver hue so
characteristic of the species. In this state they are usually known as
"kelts"; they are worthless either for food or for sport, and make their
way back to the sea, where abundant provender soon restores their
condition. Their chief food consists of herrings, haddocks, and other small
fishes. Dr. Kingston Barton recently recorded finding five full-grown
herrings in the stomach of one salmon. Although the excellence of their
flesh exposes salmon to the attacks of innumerable foes, including man,
predacious fishes, seals, and cetaceans, a few survive for many years and
attain to great size. Fish weighing from 30 to 40 lbs. are far from
uncommon; one of 60 lbs. has been taken in the Tay with rod and line, and
the same river has yielded one of upwards of 70 lbs. to the nets. The fine
sport afforded to anglers by the salmon causes a good beat on a prolific
river to be a very valuable property. Two thousand pounds was the season's
rent paid a few years ago for less than three miles of the Tweed, and the
season happened to be such a bad one that the lessee only killed thirteen
fish!
[Illustration: _Photo by A. S. Rudland & Sons._
SALMON-TROUT.
Known also as the Sea-trout, and in Ireland as the White Trout.]
Closely resembling the true salmon in habits and appearance, and sometimes
rivalling it even in size, are two kinds of sea-trout--the SALMON-TROUT,
greatly prized both for its sporting qualities and for the excellence of
its flesh, and the BULL-TROUT, a very inferior fish in both respects.
Bull-trout are not infrequently taken in the Tay weighing upwards of 40
lbs.
The Pacific Ocean has its counterpart to the Atlantic salmon and sea-trout
in several closely allied species, whereof the QUINNAT and the STEELHEAD
are the most notable. These ascend the great rivers of Western North
America in prodigious shoals, penetrating more than 2,000 miles inland to
deposit their spawn. Few of these fish survive to return to the sea. In
their emaciated condition they succumb to exhaustion and starvation; their
corpses, piled to the height of several feet, line the banks of the river
for miles, and contribute nothing to the traveller's comfort. Although
Pacific salmon are of no value to the sportsman, as they are said to refuse
any bait in fresh-water, yet they are the staple of an important trade,
tens of thousands of tons being taken and canned for export.
If we could peer far enough back into the course of time, we should no
doubt be able to identify a common stock from which all the Salmon Family
are descended. That they are all natives of fresh-water is proved by the
fact that they cannot reproduce their kind in the sea. Those that resort to
the ocean for food must be the descendants of vigorous, roving members of
the family, which, having to choose between starvation and migration,
braved the perils of travel, and became so much altered in constitution by
the liberal diet they found as to establish themselves as separate species.
Among the stay-at-homes there are many interesting and beautiful fishes.
None of them exhibit the variable nature of the family more than the common
BROOK-TROUT of British waters, and not long since men of science dignified
each of these varieties by a separate title, treating them as distinct
species. However, experiment and observation have now led to the almost
unanimous conclusion that the pygmy denizens of some hungry Highland burn,
whereof the weight must be reckoned in fractions of ounces, are of
precisely the same species as the lordly trout of deep lakes, which
sometimes scales as much as 25 lbs., and as all the other innumerable
varieties, such as the trout of the Thames, of the English chalk-streams,
and of the Irish loughs. The quality of the soil affects the food-supply,
which in turn regulates the size and appearance of the fish. Moreover,
Nature seems indifferent to the number of individuals composing the
population which the water is to sustain. If there are no pike, and
spawning-ground is abundant, there will be many and small fish; if the
contrary is the case, there will be few and large ones; the aggregate
weight per acre of water will remain the same, proportioned to the
food-supply. The American equivalent of the British brook-trout is the
RAINBOW-TROUT, a beautiful creature which has lately been widely
distributed in European waters. What is known as the brook-trout in America
really belongs to the Char group, fish of the Salmon Family, closely
resembling trout, but distinguished from them by extraordinary brilliancy
of colour. Common trout, like salmon, lose all their beauty as the
spawning-season approaches. Char, on the other hand, take gaudy colouring
at that time, the whole of the under-parts becoming clear red or
flame-colour. Unlike trout, British char never enter rivers, but spawn in
lakes. In Norway, however, char descend to the sea. The distribution of
char is indeed mysterious, nor has any explanation been offered why they
inhabit certain waters, while other lakes in the neighbourhood, apparently
equally suitable, contain none.
The GRAYLING is an elegant member of the Salmon Family, and a deserved
favourite with fly-fishers. Instead of the golden tints and scarlet spots
of the brook-trout, this fish displays the silvery colouring of the
salmon-trout. It is not at all uncommon to meet with grayling in the
chalk-streams of Southern England weighing 3 lbs. and upwards.
The POWAN is the type of another large group of salmon-like fishes,
inhabiting lakes in the temperate and subarctic regions of both
hemispheres. There are four species in Great Britain, among which may be
mentioned the mysterious VENDACE of Lochmaben, unknown to exist elsewhere.
[Illustration: _Photo by W. Reid_] [_Wishaw, N.B._
AMERICAN SALMON-TROUT FROM DIAMOND LAKE, NEW ZEALAND.
These fish were taken out of the water to be photographed, and then put
back again.]
Lastly, the Salmon Family is closed by the delicate SMELT, called in
Scotland the SPARLING, which is netted in vast numbers in the estuaries of
suitable rivers. It never ascends beyond the highest point of the tide,
where it deposits its spawn in the spring months. It is a gratifying
tribute to the good work done of late years by the local authorities in
purifying the Thames that, after a long absence, this valuable fish has
reappeared in that river, which it now ascends in considerable numbers as
high as Teddington Weir.
[Illustration: _Photo by A. S. Rudland & Sons._
SMELT.
This fish is remarkable for its peculiar smell when freshly caught, which
resembles that of the cucumber.]
Much discussion has taken place recently with regard to the question
whether salmon feed while in fresh-water. Not long ago it was announced
that they suffered from a diseased condition of the stomach during this
period, and were consequently quite unable to feed. Subsequently it was
found that the supposed diseased condition of the stomach was due to the
fishes not being perfectly fresh when they were examined. It is now known
that although salmon do not feed freely in fresh-water, yet they take a
certain amount of nutriment, such as an occasional shrimp, fly, or even
small fish, while there.
----
CHAPTER XIV.
_THE HERRING AND ITS KINDRED._
BY F. G. AFLALO, F.Z.S.
"King herring," as the trade-paper of the fishing industry rightly calls
it, is one of the chief commercial fishes of the British seas, and the
enormous North Sea herring fisheries probably support more boats and men
from all parts than any other. Europe has no very large herring; but the
TARPON of the Mexican coast, as well as another giant which occurs in the
northern waters of Australia, grows to an enormous size. All the members of
the Herring Family feed and travel near the surface of the sea, and are
therefore caught in drift-nets, miles of which are "shot" a few fathoms
from the top of the water, catching the shoaling-fish in their meshes. All
of them, too, are wanderers, most capricious in their goings and comings.
Hence the uncertainty of the fisherman's wage.
The principal kinsmen of the herring in British seas are the SPRAT and
PILCHARD, though the two kinds of SHAD, which, like the salmon, ascend
certain rivers for spawning purposes, also support a number fishermen; and
the ANCHOVY is, authorities have lately suspected, sufficiently numerous on
the British coasts to repay a regular fishery, if the men could be induced
to try the experiment and use a sufficiently fine-meshed net for this
little fish.
The HERRING of the more northern waters is larger than that of the English
Channel, 17 inches being recorded as its maximum size in the former, as
against only 12¼ inches farther south. In the Baltic, however, the writer
found the herrings still smaller than those of the English Channel. The
herring lacks the lateral line, already alluded to in other fishes; its
scales are large and thin; its under-edge is smooth and keeled; and the
male is slightly the larger of the two sexes. The SPRAT, on the other hand,
is a smaller species. It has no teeth; its belly is saw-edged; its back-fin
starts nearer the tail than that of the herring. The herring, moreover,
differs from the sprat, and indeed from all our most important fishes, in
that its eggs sink to the bottom. The eggs of almost all other sea-fish
float at or near the surface of the sea, so that the herring's spawn alone
can be damaged by the operations of the ground-sweeping trawl-net. The
shad's eggs also sink to the bottom, but are deposited in the less buoyant
waters of rivers.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
OX-EYED HERRING.
This species attains a length of several feet.]
The PILCHARD, the all-important fish (together with mackerel) on the
south-west coast of England, is of a more decided green hue than either of
the foregoing. Its scales are large and coarse, and its back-fin starts
closer to the head than in the rest. The pilchard of Cornwall and the
sardine of the Mediterranean are one and the same fish in different stages
of growth--that is to say, the pilchard is a grown-up sardine. The late
Matthias Dunn of Mevagissey was one of the first practical fishermen to
accept this identity, and the flourishing sardine factory at his native
town bears lasting witness to his enterprise. Although, from the economic
standpoint, we associate the pilchard with the extreme south-west of the
English Channel, the fish finds its way to more eastern counties. The
writer has found it at both Bournemouth and Ventnor; and it is taken,
though sparsely, in the herring-nets of the North Sea fleets.
The ANCHOVY, smaller than any of the foregoing, may be distinguished by its
projecting, shark-like snout and deeply cleft mouth. It is seen in England
only pickled for table purposes, but the writer used fresh anchovies for
bait almost daily during a stay of four months on the shores of the
Mediterranean.
The two shads--the ALLIS SHAD and TWAITE SHAD--are in some respects, though
less important commercially, the most interesting of the family. Their
habit of coming up rivers to spawn, like salmon, has been already noticed,
but they appear to be more difficult to please than the other fish. The
Severn used to be a noted shad-river, but the fishery has fallen off of
late years. The ALLIS SHAD grows to a weight of 7 or 8 lbs., and its pale
green and silver scales are varied by some darker spots at irregular
intervals on the shoulders and sides. The edge of the belly is serrated,
like that of the sprat. The fish has a curious transparent eyelid, and its
other peculiarities include an abnormally large number of gill-rakers,
through which the water filters much as it does through the "whalebone" of
whales. Its food is said to consist of small fishes and shrimps, as well as
of vegetable substances. Though usually caught, for market purposes, in a
seine-net, which is slipped round the shoal in shallow water, the shad is
now and then taken on the hook, and instances of this are on record in the
neighbourhood of Deal. The rivers of Morocco are very productive of shad,
particularly the BOUREGREG at Rabat, and the UM ERBEYA at Azimur. At the
latter town the writer has bought newly caught shad weighing 5 or 6 lbs.
for native money equivalent to as many pence, and very excellent fish they
proved in camp. The TWAITE SHAD is a somewhat smaller fish, attaining to a
maximum weight of perhaps a couple of pounds. It is not known to differ
materially in habits from the larger species.
Reverting for a moment to the herring as a type of the family, a few words
may be said on some very interesting facts in connection with its
life-history and commercial uses. In the first place, the fact that the
spawn sinks to the bottom is of more importance than would at first sight
appear, since it not only exposes this spawn to disturbance by the trawl,
but also subjects it to the voracity of cod, haddock, and other
ground-feeding fishes. Some little protection is afforded by a natural
provision which enables the eggs to adhere to stones and weeds, but this
cannot in the long-run be of much service against prowling fishes. The eggs
of the shad, which likewise sink (in fresh-water), do not adhere in this
way.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
QUEENSLAND LUNG-FISH.
Known also as the Dawson River Salmon, on account of the colour and flavour
of its flesh.]
The migrations of the herring, again, have furnished almost as much
material for argument to marine biologists as the migrations of birds in
ornithological circles. Older naturalists described marvellous Arctic
journeyings with careful attention to detail, much of which is now
repudiated. Later theories hold that the shoals of herrings simply move,
according to changes in the weather and temperature, backwards and forwards
between the shore and the deeper water outside; and so far as the fishermen
are concerned, the mere fact of the fish moving at any season of the year
beyond reach of their drift-nets, which work at only moderate distances
from the land, would be quite sufficient to convince them that the absent
fish had departed on world-wide travels. Much of the former acceptance of
these extensive migrations may have been due to confusion between the
goings and comings of the different races of herrings now recognised by
biologists. It is also probable that, when the identity and movements of
these different "races" are more firmly established, we shall be able to
clear up many of the difficulties at present surrounding the spawning-time
of the herring, and to show that it does not, as sometimes alleged, deposit
its spawn at every season of the year indiscriminately, but that some
herrings spawn at one season, some at another. Although the herring is not,
individually and by comparison with some other sea-fish, an enormously
fertile fish, its numbers must be fairly large, when we bear in mind that
something like 50,000 crans a week are, in good seasons, packed in
Shetland alone. Taking, as an average, 750 fish to the cran, this gives a
weekly curing of not far short of 40,000,000 of herrings in a single
fishery. Owing indeed to the property, already noted, of adhering to stones
and rocks, it is improbable that even the trawl troubles the eggs to any
appreciable extent, as the stony ground on which the herrings generally
spawn is not suited to the operations of the trawler. The spawning and
life-history of the herring are, in fact, the converse of those of the
plaice. The former deposits its eggs on the ground close inshore, and the
young herrings, almost as soon as they are hatched, steer for the open sea
and live near the surface of the water. The flat-fishes, on the other hand,
deposit eggs that float at the surface some distance from the shore; and
the young plaice and soles, when hatched, come inshore and take up their
residence close to the bed of the sea.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
AUSTRALIAN PILCHARDS.
Distinct from the British species.]
It would be improper to conclude this account of the Herring Family without
a passing reference to the commercial mixture known as "WHITEBAIT." Until
comparatively late in the last century whitebait was regarded, even by
scientific men, as a distinct species, and there were even some who
declared that they had identified peculiar characters. It is now, however,
common knowledge that the so-called "whitebait" is neither more nor less
than a mixture of young herrings and sprats, the former predominating in
summer, the latter in winter. Other fishes are also found in the dish, and,
appropriately enough, at a recent banquet given by the Worshipful Company
of Fishmongers, at which the writer had the pleasure of "assisting," a
plate of whitebait was found to include no sprats, but the fry of herrings,
gurnards, and sand-eels: this was in the month of July. Whitebait are
caught in special fine-meshed nets in river-estuaries; and although they
make a capital dish for the epicure, the large supplies needed for the
restaurants probably entail a most regrettable sacrifice of valuable
food-fishes, which, if left a year or two, would provide food for ten times
the number of consumers. It would, however, be too much to expect that
epicures should give up such an unrivalled dish for this cause. Moreover,
if these little fishes were not captured by man, it is highly probable that
a large proportion would fall victims to birds or other fishes.
----
CHAPTER XV.
_BONY PIKE, BOW-FIN, STURGEON, REED-FISH, AND BICHIR._
BY W. P. PYCRAFT, A.L.S., F.Z.S.
The present chapter deals with the remaining forms belonging to that great
assemblage of fishes known as the Bony-mouthed group, which includes all
the members of the class save the Lung-fishes on the one hand and the Shark
Tribe on the other.
This great assemblage, as we have already remarked, is divided into two
sections--the Fan- and Fringe-finned Fishes. The fishes presently to be
described belong partly to the one and partly to the other of these
divisions, and were at one time, together with the Lung-fishes, regarded as
nearly allied, and as forming but a single group, which, on account of the
structure of the scales, was known as the Enamel-scaled group.
The BONY PIKE, the BOW-FIN, and the STURGEON are the last of the Fan-finned
Fishes.
The BONY PIKE, or GAR-PIKE, is an inhabitant of the fresh-waters of North
America, and has the most completely ossified skeleton and the most
perfectly jointed backbone of all the fishes, whilst externally it is
covered with a complete armour of thick, quadrangular scales coated with
enamel. Three distinct species of this family are known, all of which are
of large size, attaining a length of 6 feet. They are carnivorous in their
habits, lying in wait among the reeds, and rushing out to seize their prey
as soon as within range. In the Mississippi, great lakes, and rivers of
South Carolina bony pike are especially abundant, occurring at times in
such numbers as to fill the shad-nets and render the fishery for many days
impossible. The larger members are said to be as aggressive as sharks, and
remarkably tenacious of life.
[Illustration: _Photo by A. S. Rudland & Sons._]
[Illustration: _Photo by Scholastic Photo. Co._] [_Parson's Green._
BONY PIKE.
One of the very few survivors of the ancient group of Enamel-scaled
Fishes.]
The geographical distribution of the BOW-FIN closely corresponds with that
of the bony pike. It is an extremely common fish, and, though worthless for
food purposes, has yet been deemed worthy of a number of different names,
such as GRINDLE, DOG-FISH, SAWYER, MUD-FISH, and LAWYER-FISH. At one time
it was regarded as a near ally of the Herring Tribe, but modern research
has shown this view to be erroneous. The bow-fin attains a length of about
2 feet, and is very voracious, preying both upon other fishes and aquatic
insects and shrimps. It has a habit of coming frequently to the surface to
breathe, especially when the water is foul, taking in large mouthfuls of
air. When near the surface, it is said to utter a bell-like note, probably
caused by the escape of air from the air-bladder. During the
breeding-season the male takes entire charge of the eggs.
[Illustration: _Photo by A. S. Rudland & Sons._
STURGEON.
The air-bladder of the sturgeon is used for making isinglass, its roe for
caviare.]
The STURGEONS differ from the other fan-finned fishes in many particulars.
To begin with, the skeleton is almost entirely cartilaginous instead of
bony, whilst externally the body is either naked or covered with bony
bucklers, arranged symmetrically. The snout is prolonged into a more or
less shovel-shaped beak, used for turning over the mud at the bottom of the
water in search of prey, and in some forms this becomes further developed
into a spoon-shaped paddle, constituting one of the most remarkable
appendages of fishes.
[Illustration: _Photo by A. S. Rudland & Sons._
STERLET.
A smaller species of the Sturgeon group.]
Sturgeons grow to a large size, and are the largest of the fresh-water
fishes of the northern hemisphere. The GIANT STURGEON of the Black and
Caspian Seas and the Sea of Azoff attains a length of 24 feet, and
sometimes more, specimens of 3,200 lbs. weight having been recorded.
On account of the wholesomeness of their flesh, sturgeons are highly
esteemed wherever they are found. In Russian rivers they are very abundant,
regular fishing-stations being established for their capture. The approach
of a shoal of fish is announced by a watchman, and it is said as many as
15,000 sturgeon have been captured at one of these stations in a single
day. Should the fishing be suspended for a short time, the fish assemble in
such numbers as to form a solid mass, completely blocking a river 400 feet
in width and 25 feet in depth.
[Illustration: _Photo by A. S. Rudland & Sons._
BICHIR.
A second representative of the Enamel-scaled group.]
From the roe of these fishes caviare is made, and isinglass from the inner
lining of the air-bladder. But the best-flavoured flesh and the finest
caviare are obtained from a comparatively small form, the STERLET, a
species which does not exceed a yard in length. It is common in the Black
and Caspian Seas, the Siberian rivers, and the Danube as far as Vienna.
[Illustration: _Photo by Scholastic Photo. Co._] [_Parson's Green._
BICHIR.
Note the remarkable finlets on the back and the peculiar structure of the
breast-fins.]
With the Sturgeons we come to the end of the Fan-finned Fishes. The
Fringe-finned group are represented to-day only by the BICHIR and the
REED-FISH. These are extremely interesting forms, if only because they are
the sole survivors of a once numerous tribe, the remains of which occur as
fossils in some of the oldest geological formations. They are known as
Fringe-finned on account of the fact that the rays which support the
fin-membrane in the paired fins are ranged round a lobe-shaped base,
instead of running directly backwards to the body. As in the bony pike, the
body is clothed externally by large quadrangular bony plates of
considerable thickness, and coated with a layer of enamel.
The BICHIR, which is found in the Nile and other tropical rivers of Africa,
is easily recognised by the peculiar structure of the back-fin, which takes
the form of a series of detached finlets, varying in number from eight to
eighteen. The length attained by the bichir is about 4 feet. Gill-breathing
is supplemented by the air-bladder, which is used as a respiratory organ,
the expired air escaping by a slit, known as the "spiracle." The young
bichir breathes, like a tadpole, by means of large external gills,
projecting backwards on each side of the head; later these are replaced by
the more efficiently protected internal gills.
The only surviving relative of the bichir is the REED-FISH of Old Calabar,
which differs by its eel-like form and the absence of the hinder paired
fins.
----
CHAPTER XVI.
_SHARKS AND RAYS._
BY F. G. AFLALO, F.Z.S.
Two prevalent errors with reference to sharks continually recur in England.
The first is local, and has reference to the absence of "proper" sharks,
whatever that may mean, from British waters. The second, of wider
application, holds that all sharks are dangerous to man. When, some few
years ago, the writer addressed a letter to the Times newspaper, warning
yachting-men against summer bathing in deep water in Cornwall, a host of
critics accused him of a tendency to pose as an alarmist, and insisted that
he was confusing sharks with dog-fish. Apart from the fact that the
distinction between the two groups is in some cases extremely slight--it
does not even rely on size, for there are dog-fishes which attain to larger
dimensions than the smallest sharks--these gentlemen were wholly in error,
since four sharks at any rate are very common in Cornish seas, and even
occur in lesser numbers on other parts of the British coasts. The largest
of these, the great BASKING-SHARK (of which a photograph, taken at
Mevagissey, is given below), illustrates in its harmless person the fallacy
of condemning all sharks as man-eaters, since in this, the largest of its
race, we have an absolutely innocuous fish. From its habit of lying at the
surface with the large back-fin erect, it is also known as the Sail-fish,
while the equally appropriate name of Sun-fish sometimes causes confusion
with other British fishes properly so called.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
WOLLIBONG, OR CARPET-SHARK.
The leaf-like processes surrounding the head serve to attract prey, while
the shark lies concealed on the sea-bottom.]
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
SPOTTED SHARK.
Note the peculiar shape of the tail, and the aperture behind the eye, known
as the "spiracle."]
[Illustration: _Photo by S. Dalby Smith_] [_Mevagissey._
BASKING-SHARK.
Regularly hunted on the west coast of Ireland for the sake of the oil
obtainable from its liver. Note the keel by the side of the tail.]
A commoner British shark (in the limited space allotted, British species
must be allowed prior claims) is the BLUE SHARK, small examples of which,
weighing 30 or 40 lbs., the writer has often killed with the rod at
Mevagissey. When thus hooked, this fish has a curious and very trying habit
of revolving rapidly in the water, scoring its own granulated skin with the
line. The PORBEAGLE-SHARK, another Cornish species, is of thicker build
than the last, and swims with far less graceful movements. It is a deep
brown colour above, and its general outline may be likened to that of a
torpedo. The FOX-SHARK, or THRESHER, so often seen on hot summer days
leaping out of water among the pilchard-shoals, is easily recognised, even
at considerable distances, by the disproportionately long upper lobe of the
tail-fin. This is the shark which attacks certain of the Whale Tribe. Many
who stay at home find it agreeable to cast doubt on the story; but the
writer has, in Australian seas, witnessed the sight of two of these sharks
flinging themselves on the back of an apparently exhausted whale in such
unmistakable circumstances that the only alternative (which the reader may
accept, if preferred) is to suppose that they were all congenial playmates.
Before specifying some general characters of this interesting group of
predatory fishes, it may be as well briefly to summarise the BRITISH
DOG-FISHES; for the HAMMERHEAD-SHARK, very common in southern seas, is so
rare a visitor to Britain as to be negligible in an epitome of the group.
The dog-fishes, then, which trouble fishermen are the SMOOTH HOUND and
ROUGH HOUND, the NURSE, the PICKED DOG, and the SILVER DOG, or TOPE. The
NURSE and ROUGH HOUND are spotted leopards of the sea, and the latter has a
very curious property. If a fresh-caught "row-hound," as the fishermen
pronounce the name, be put in a basket or boat's well with pollack and
other fishes, the points of contact will be marked by discoloration of its
neighbours. This is probably due to some acrid and bleaching secretion of
the row-hound's skin, for which some economic use might possibly be found.
The PICKED DOG, or SPUR-DOG, has very sharp spines in front of both
back-fins, and has therefore to be handled by the fishermen very
cautiously, often punishing their hands badly when entangled at night in
the nets. Of SMOOTH HOUNDS there are two species or varieties, between
which there is some confusion, and in one at any rate there are interesting
anatomical peculiarities in the unborn fish (like many other sharks and
dog-fishes, the smooth hound bears living young instead of depositing
eggs), any account of which would obviously be out of place in so short a
description.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
OCELLATED DOG-FISH.
So called from the presence of the eye-like spots on the body, two of which
can be seen above the breast-fins.]
[Illustration: _Photo by A. S. Rudland & Sons._
INDIAN STRING-RAY.
The tail is armed with a powerful poison-spine.]
Generally speaking, then, the sharks are cartilaginous fishes, having the
upper lobe of the tail larger than the lower, a shovel-shaped snout, and
the crescent-shaped mouth beneath the head. Another peculiar feature of the
group is the presence of breathing-spiracles behind the eyes; while the
latter have a manner of blinking not found in other fishes. Of the teeth,
which differ in structure from those of other kinds of fishes, there are
several rows. The gill-openings are lateral, and usually number five,
though one species has six and another seven. With the exception of the
afore-mentioned BASKING-SHARK and the PORT JACKSON SHARK, which the writer
met with in Australia, they are all more or less dangerous; and when of
insufficient size to be harmful to man, do great damage among the lines and
nets of the fishermen. Indeed, the late Matthias Dunn of Mevagissey
seriously urged on the Admiralty to dynamite them in the interests of the
fishing industry. Most of the sharks deposit their eggs in the curious
oblong vessels known by those who pick up the disused cases on the
foreshore as "purses"; and these attach themselves to rocks and stones by
long tendrils that cling to every support. A number of species (the
PORBEAGLE and TOPE among British kinds), however, bring forth their young
alive.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
HORNED OX-RAY, OR DEVIL-FISH.
This species and its allies attain enormous proportions. One taken at
Barbadoes required seven yoke of oxen to draw it.]
Between the Sharks and Rays there is a curious and interesting link in the
form of the MONK-FISH, or ANGEL-FISH, which is common on all sandy shores,
and a frequent victim of the trawl. Such local names as Mongrel-skate and
Shark-ray indicate a widespread acceptance of its intermediate position
between the two groups under notice. Like some of the sharks already
noticed, it produces living young, and its maximum size may be set down as
at any rate over 7 feet. The writer measured and weighed one trawled in
Bournemouth Bay during the summer of 1896. Its length was nearly 4½ feet,
and its weight rather less than 50 lbs. Like many of the rays, this species
feeds to a great extent on flat-fishes.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
WHIP-TAILED STING-RAY.
Sting-rays are abundant in tropical seas.]
In outward form the monk-fish, though it is in reality more nearly allied
to the sharks, brings us by an easy transition to the flattened RAYS, with
their long whip-like tails and pointed snouts. There are a dozen, or rather
more if we count casual visitors, of these skates and rays in British seas,
the largest being the great EAGLE-RAY, examples of which have been recorded
of the enormous weight of 1,000 lbs. Many of the smaller kinds are studded
with sharp spines, curved in some species, and the THORNBACK owes to these
its trivial name. All these rays, in fact, have some form or other of
formidable offensive and defensive apparatus. The STING-RAY has on its tail
a fearful serrated dagger, 6 or 8 inches long in large examples; while the
TORPEDO- or NUMB-FISH has electric organs in the head, with the aid of
which it can give a shock sufficiently strong to paralyse the fishes on
which it feeds.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
SHOVEL-NOSED SKATE.
Known also as the Halavi Ray.]
Two interesting peculiarities of the rays deserve notice in concluding this
chapter. The first is that their egg-purses, instead of attaching
themselves with filaments to weeds and rocks, like those of the sharks, are
provided with a sticky secretion which answers the same purpose of
anchoring them in security from currents that would carry them out into
deep, cold water. The second is the sexual difference in the teeth, which
are pointed in the male and flat in the female. Whether this difference in
the teeth (which may be likened to that between the bills of the male and
female Huia-bird of New Zealand) indicates a corresponding difference in
food, or, on the other hand, some co-operation between the sexes in
procuring it, is an interesting question that our present slight knowledge
of the habits of these fishes does not enable us to answer.
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
PAINTED SKATE.
So called on account of its conspicuous coloration.]
Finally, attention must be drawn to the remarkable transformation which the
breast-fins and tail have undergone. The former have developed into
powerful swimming-organs, locomotion being effected by their undulatory
movements, instead of by similar movements of the whole body, or by
side-to-side motions of the tail, as in other fishes. Whilst the latter, no
longer used in swimming, has either been reduced to a mere vestige, as in
the HORNED OX-RAY, or has become developed into a long and tapering
"whiplash," provided with a poison-spine. In such cases the long tail is
used to encircle prey, and at the same time to force the victim on to the
deadly spine.
----
_BOOK V. JOINTED ANIMALS._
----
CHAPTER I.
_THE CRAB AND SCORPION GROUPS._
BY W. F. KIRBY, F.L.S.
This section of animals is often called a "sub-kingdom," and differs from
back-boned animals in having the framework of the body outside. That is,
instead of a skeleton, Crabs, Spiders, Centipedes, and Insects are
protected either by a hard shelly casing, or by a tough skin, to which the
muscles are attached; and this arrangement renders them much stronger and
much less susceptible to injury, in proportion to their size, than
vertebrate animals. They have cold blood, generally of a white colour; and
their bodies and limbs are usually composed of a considerable number of
separate joints.
[Illustration: _Photo by E. Connold._
BARNACLES.
A species which commonly attaches itself to ships' bottoms and floating
wreckage.]
The group is a very large one, and it is probable that there are at least
300,000 different kinds of insects already known, while the total number of
species now existing is estimated by different entomologists as from two to
ten millions. It is, therefore, no exaggeration to say that every word of
our brief account of the Insects represents from ten to twenty known
species at least. The other classes of the group are also very numerous.
Our account must necessarily be very short; the characters of the principal
classes of the Jointed Animals are referred to in their places.
CRABS, LOBSTERS, SHRIMPS, WOOD-LICE, BARNACLES, ETC.
[Illustration: _Photo by W. P. Dando, F.Z.S., Regent's Park._
A PAIR OF BARNACLES.
The larger size of this photograph exhibits more structural details than
the last.]
Jointed animals are generally provided with one pair of long jointed
organs, called "antennæ," a naturalised word derived from the Latin, in
which language _antenna_ means a sail-yard. They are often called
"feelers," and usually fulfil this function at least; but they are also
frequently organs of smell, and sometimes probably of hearing and other
senses. One peculiarity of the CRAB and LOBSTER group is that they are
generally furnished with two pairs instead of one pair of these organs.
[Illustration: _Photo by W. P. Dando, F.Z.S._] [_Regent's Park._
ACORN-BARNACLE.
The general appearance is so different from the Stalked Barnacle that it is
difficult to believe the two belong to the same group.]
They are nearly all aquatic animals, by far the larger portion being
marine, and they breathe with gills. They are provided with a hard
calcareous or horny covering. The head is not separated from the trunk, as
in insects; and they are provided with a number of jointed organs, usually
classified as three pairs of jaws, three pairs of foot-jaws, and five pairs
of legs in the more typical families; but in the smaller and more aberrant
species the number is more variable. In their early stages they frequently
pass through very extraordinary changes of form, but after assuming their
adult shape they grow by casting their shells at intervals.
We will now notice a few typical examples of the different groups of these
creatures.
The BRINE-SHRIMP is a little reddish creature about half an inch long,
which prefers the concentrated solution of brine-pits to sea-water. It has
eleven pairs of legs, and, notwithstanding its name, the front portion of
its body is considerably broader and flatter in proportion than that of a
real shrimp, the other half consisting of a jointed tail.
BARNACLES were formerly considered to be shell-fish, but are now usually
classed with the crabs and lobsters, because, when they are young, they
appear as freely swimming creatures, with one eye, two antennæ, and six
pairs of jointed limbs. When they grow larger, they fix themselves to a
rock or some other object by the head, and develop a shell, usually
composed of several pieces. The commonest is the ACORN-BARNACLE, the white
shell of which, measuring rather less than an inch across, swarms on rocks
at the seaside. It is shaped like a limpet, but open at the top. The
GOOSE-BARNACLES hang down by a stalk, and their jointed shells more
resemble those of a mussel than that of a limpet, though they are composed
of several pieces. Various species similar to both those mentioned are
found on piers, rocks, the bottoms of ships, and even sometimes on the skin
of whales.
In dark cellars in the country, under loose bark, or under pieces of wood
which have been left in the fields, we often see creeping about brown
creatures about half an inch long, with jointed bodies and antennæ, and
short jointed legs. They are called WOOD-LICE, and several species roll
themselves up into a ball when alarmed. These creatures feed chiefly on
decaying vegetable substances; and there is a larger marine species much
like them, which is common in holes and crannies in the rocks on the
seashore.
There are other curious creatures, called WHALE-LICE and FISH-LICE, which
are parasitic in their habits. Some of these look like spiders, and one or
two have enormously long legs; but others are of strange and almost
indescribable forms, and sometimes without legs at all. One species, found
on the sprat, has two long appendages at the end of its body not unlike a
pair of compasses.
[Illustration: _Photo by W. P. Dando, F.Z.S. Regent's Park._
WOOD-LOUSE.
A land representative of a numerous marine group.]
SHRIMPS and PRAWNS are red when cooked, but when alive are very pretty
semi-transparent objects, which may be seen swimming about through the
glass of aquariums placed against the wall. Prawns are larger than shrimps,
and have a strong serrated spine in front of the head. Shrimps and prawns,
of which several kinds are found off the British coasts, generally prefer
shallow water, with a sandy bottom. In most of these the first two pairs of
feet are divided to form a pair of pincers at the extremity; but in such
small creatures this is easily overlooked, unless special attention is
directed to it. It is different with the LOBSTERS and CRAYFISH, which much
resemble shrimps in form, but are very much larger, and armed with a pair
of very large pincer-like claws, in addition to the other legs. Lobsters
live in the sea, in holes in the rocks, into which they dart backwards, and
there protect themselves with only the head and claws projecting at the
opening, ready to face any intruder. Crayfish, which are smaller, live in
holes in the banks of brooks and rivers. There are many species, some of
large size and bright colours. The COMMON LOBSTER is black when living, but
other species are red, blue, or variegated.
[Illustration: _Photo by W. P. Dando, F.Z.S._] [_Regent's Park._
SHRIMP.
A species which plays an important part in the food-supply of London.]
Sometimes, if we pick up a whelk-shell on the beach, we shall find it
inhabited, not by a mollusc, but by a crab, with its legs and claws wedged
together, so as to fill the aperture completely--one claw, much larger than
the other, resting in front; and if we pull it out, we shall find that,
though the front of its body and the legs and claws are hard, like those of
an ordinary crab, it has a long, soft, fleshy tail, absolutely defenceless
and unprotected. Crabs belonging to this curious section are called
HERMIT-CRABS, and protect themselves by taking possession of shells which
they have either found empty or appropriated by the easy and economical
process of devouring the owners. The few species found on the British
coasts are all small, and more frequently noticed in whelk-shells than in
any others; but tropical species attain to a considerable size, and may
sometimes be found in shells measuring 3 or 4 inches across at the opening.
[Illustration: _Photo by C. N. Mavroyeni_] [_Smyrna._
FRESH-WATER CRAB.
In general appearance very similar to the common shore-crab.]
Crabs are distinguished from the lobsters by their compact form, and by
having the short tail turned in under the body. There are a great number of
species, differing much in size, shape, and appearance. One of the best
known in England is the large EDIBLE CRAB, which may often be seen in
fishmongers' shops, and, unlike the lobster, does not change much in colour
when boiled. Every visitor to the seaside must have seen numbers of the
little greenish SHORE-CRABS, running about on the sand, or over
seaweed-covered rocks, at low tide. These small crabs are harmless, but
large kinds are able to give a very severe pinch. It is related that when
the great chemist Sir Humphry Davy was a boy he used to maintain that pain
was no evil, until a large crab gripped his toe one day when he was
bathing, after which he changed his opinion.
[Illustration: GOLIATH BEETLE.
West Africa. (Half natural size.)]
[Illustration: BRAZILIAN BEE.
(Enlarged one-third.)]
[Illustration: GRASSHOPPER.
From Somali Land and Aden. (Slightly reduced.)]
[Illustration: CANDLE FLY.
From Ceylon. (Slightly reduced.)]
[Illustration: AUSTRALIAN ROBBER-FLY.
(Slightly reduced.)]
[Illustration: JAPANESE ANALOPHUS.
(Enlarged one-third.)]
_Photos by W. P. Dando. F.Z.S. Regent's Park._ _Printed at Lyons,
France._
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
SPIDER-CRAB.
An active sea-scavenger.]
[Illustration: _Photo by W. Saville-Kent, F.Z.S._] [_Milford-on-Sea._
BLUE CRAB.
Much esteemed for the table.]
[Illustration: _Photo by W. Saville-Kent F.Z.S._] [_Milford-on-Sea._
FIGHTING CRABS.
The males are remarkable for having one large scarlet claw, the other being
rudimentary (the females possess two small claws only). The eyes also are
seated at the end of long stalks.]
Some crabs are smooth and shining, but others are covered with bosses,
excrescences, and spines, which give them a very formidable appearance, and
must be a useful protection against any enemies to whose attacks they are
exposed. In many species one of the two great claws is always much larger
than the other. Some have round bodies, others are oval or nearly square;
some have short legs, and others very long ones. The species differ much in
their habits; and in tropical countries there are land-crabs which live
entirely on shore, and others which are amphibious, and climb
cocoanut-trees to get at the nuts. As a general rule, however, crabs are
carnivorous and marine, and play the part of sea-scavengers.
The KING-CRABS differ very much from any now living in the British seas,
but are generally considered to be allied to the Trilobites, an extinct
family which appears to have been extremely numerous in very ancient seas.
King-crabs are 2 or 3 feet long from the front of the body to the end of
the tail. The front part of the body is entirely covered by a curved oval
shield, while the hinder part of the body is much narrower, and armed at
the sides with strong teeth directed backwards, and also with a long and
strong spear, something like that of a sword-fish on a small scale, as long
as the rest of the body. The few species known exhibit an instance of what
is called "discontinuous distribution," since they are found only on the
coasts of the Moluccas, East Indies, and the Southern United States and
West Indies.
SCORPIONS, SPIDERS, AND MITES.
These creatures form a peculiar group in which there are only two principal
divisions of the body, the head and thorax being fused into one mass, and
the abdomen forming a separate division. In the Mites, however, the body
forms a single round or oval mass, even the division between the thorax and
the abdomen having disappeared. The members of the group have no antennæ,
but two pairs of jaws and a pair of palpi, frequently very long, and armed
with a pincer-like arrangement at the end, in which case they are called
"foot-jaws." Except in some of the mites, which have only four or six, all
the group have eight legs. They pass through no metamorphosis, but moult
several times after quitting the egg before attaining their full growth.
They have frequently several pairs of simple eyes, but no compound eyes
like the large pair on the head of most insects.
In the SCORPIONS, of which there is a considerable variety in different
parts of the world, the united head and thorax are comparatively short; but
the abdomen is very long, and divided into a broad half, consisting of
seven segments, and a narrow tail of five very movable segments, besides a
sharp, curved sting at the extremity. There are from three to six pairs of
eyes on the head and thorax, and in front of the body projects a pair of
very large pincer-bearing foot-jaws. Scorpions are generally of a yellowish
or black colour; and the largest black scorpions of Africa and India
sometimes measure as much as 9 inches in length. They are nocturnal
creatures, hiding under stones, or in holes in the ground, or in crevices
in walls during the day. They kill the insects and other small animals on
which they feed with their stings, the sting of one of the large black
scorpions, like that of the large tropical centipedes, being as painful and
dangerous as that of a snake. There are a few small and comparatively
harmless species found on the shores of the Mediterranean, but most of the
scorpions inhabit warmer countries.
[Illustration: _Photo by Highley._
EGYPTIAN SCORPION.
A fairly large and venomous representative of the group.]
The JOINTED SPIDERS are creatures 1 or 2 inches long, remarkable for having
the head and the segments of the thorax separated from each other, so as to
form distinct divisions of the body. They have rather long and very hairy
legs, and only one pair of well-developed eyes, another pair being
rudimentary. Some species are diurnal and others nocturnal in their habits.
They feed on insects, and sometimes on small birds, etc., and can inflict a
very painful bite. They are found in South-eastern Europe, Africa, Southern
Asia, and from the Southern States of North America south to Chili and
Argentina.
[Illustration: _Photo by Highley._
EGYPTIAN SCORPION.
Shows the sting uplifted for attack.]
The FALSE SCORPIONS, or BOOK-SCORPIONS, are small animals resembling
scorpions in shape, but with no sting, and the abdomen not narrowed into a
tail. They are sometimes found in houses among dusty old books, as well as
out of doors among moss, or under stones or bark. Sometimes they cling to
the legs of flies; they are believed to feed on mites and other small
creatures, but not to injure the flies, only employing them as a convenient
method of being conveyed from one place to another.
[Illustration: Photo by Highley.
TREE TRAP-DOOR SPIDER OF BRAZIL.
Trap-door spiders are plentiful in some parts of Europe, but there is only
one British representative of the family.]
The WHIP-SCORPIONS are not unlike scorpions, and have large claws, but the
front legs are very long, slender, and whip-like, and there is either no
tail, or else a long, slender, whip-like one without a sting. They are
inhabitants of warm countries, and, rightly or wrongly, are reputed to be
venomous. Different species measure from 1 inch to 4 or 5 inches in length.
The curious HARVEST-MEN have two eyes, a small, compact, oval body, large
pincers, and very long, slender legs, longer and more slender in proportion
to their size than those of crane-flies, and equally liable to be broken
off, if the owner is roughly handled. They feed on plant-lice and other
small insects.
We now come to the large and important group of SPIDERS, which more
frequently attract attention in England than any others of the group. The
abdomen is not usually divided into distinct segments, and is connected
with the thorax by a short stalk. Spiders have strong, poisonous jaws,
which make some of the larger species formidable even to man, and several
pairs of eyes; while many possess an apparatus for spinning a strong silken
web, in which they entangle their prey, consisting in England chiefly of
flies and other winged insects.
[Illustration: _Photo by Highley._
HOUSE-SPIDER.
Exhibits the four pairs of legs characteristic of the group.]
The largest known spiders are usually placed first in the series. These are
the great BIRD-CATCHING SPIDERS of South America, some of which have bodies
3 inches long, and strong, hairy legs. These large spiders have now been
proved not only to feed on insects, but occasionally on humming-birds, and
even sometimes on larger birds, such as finches.
The TRAP-DOOR SPIDERS are allied, but smaller, perhaps averaging about an
inch in length. They construct a silken gallery in the ground, with a round
door, which they shut behind them when they enter. There is only one
species in England, which does not form a trap-door, but a silken tube. If
any insect settles on it, the spider clutches it from within, tears a hole
in the tube, drags its prey inside, and then repairs the rent.