CRABS AND LOBSTERS.
The professional crab and lobster catcher has to provide himself with
“pots” and “hullies” for the taking and storing of his crustaceans for
the market, and ultimately the table. As we are concerned more with the
unmarketable smaller fry, to which the fisherman almost denies the name
of crab, we need no such cumbrous paraphernalia; our handy open basket,
with its stock of glass jam-jars, is all we require.
Our occupation to-day consists in turning the large stones at low-water
in the “long drang,” and lifting the heavy tapestry of olive weeds that
covers the rocks. In this occupation we shall encounter several species
of the crab class, or the Crustacea, as naturalists term that division
of the animal kingdom which includes the crabs, lobsters, shrimps,
prawns, and barnacles. The crab and the lobster of the fishmonger’s
shop are creatures that, as adults at least, are chiefly found in deep
water, and therefore do not concern us much. But in seeking for other
sorts we shall turn out no end of young specimens of the Great Crab,
up to three or four inches across the longest part of his _carapace_,
as the upper “shell” of a crab is styled in the precise language of
science. As this Great Crab, from its occasional appearance on our
tables and its large size, is the best known of the whole tribe, we
shall do well to use it for a type of the Crustacea, and write a few
words concerning it. Any of these small specimens that we can catch
under the stones or in rock-holes will serve our purpose, and having
taken the precaution to hold his longest diameter between our thumb and
forefinger, so that he may not inflict a painful nip with his pincer
claws, we shall be able to examine him at leisure.
The most striking feature of the Great Crab (_Cancer pagurus_) is
its heavy pincer-claws (_chelæ_), which in a really large male, or
Jack-crab, assume enormous proportions. I measured a specimen that a
few months since found its way to the cooking pot at home. Across the
back, measuring the “shell” only, it was ten and a quarter inches long
by six and three-quarters from back to front. I took no account of the
walking feet, but the big _chelæ_ measured sixteen and three quarter
inches from the root to the tip, and their girth at the thickest part
of the “hand” was eight inches and a half. One of these large specimens
of the Great Crab always reminds me of a well-baked pie, when I look at
him tucking his legs beneath his roof. It is not alone the substance of
his shell and the brown tint that suggests pastry, but there are those
deep lines in the frontal margin, marking off the “quadrate lobes” of
the scientific describer, that at once reminds you of the marks the
cook impresses upon her paste with a fork. Then, of course, there is
the pale undercrust; and the resemblance will be strengthened when you
observe the voracious Shore Crab, after dining upon a younger brother,
holding the empty carapace to his mouth in his pincer-claw, like a
piece of pastry, whilst he nibbles at the edge until it is all gone.
So much for this fanciful notion; now let us to business. This shell
or carapace of the crab has no more than the merest superficial
resemblance to the shells of oysters or other shell-_fish_, falsely
so-called. Its relationship is much closer to the horny integuments
of beetles and other insects. These are formed of a substance called
_chitin_, and of _chitin_ also are all the hard parts of a crab
composed, with the addition to it, when in a fluid condition, of
calcareous matter, which hardens upon a short exposure to the air
or water. Where the limb is to bend the calcareous salts are not
deposited, so we find the joints covered with a membrane of soft chitin
alone.
The Crustacea belong to that grand division of the animal kingdom
known as the Arthropoda, _i.e._, animals whose bodies consist of a
series of variously-shaped segments, the skeleton being external, and
giving more definite form to those rings, which are placed edge to
edge, and some of which have limbs attached to them. Taking a bird’s
eye view of the crabs, and seeing only the continuously solid surface
of the carapace, it would be difficult to accept this statement; more
especially should we stare hard at the crab’s back if we were told
that the typical number of such rings or segments in the Crustacea is
twenty (some authorities say twenty-one). But if we turn the crab over
so that we can get a fair view of his smooth white underside, we begin
to think there may be something in this ring theory after all, for the
undercrust is not solidly continuous like the upper, but marked off
by grooves to indicate the segments. The idea is that in the original
progenitor of the race the whole twenty segments were distinct and
had independent movement, but that in the process of evolution of the
various species it has served their purpose in life to have some of
these segments soldered together. And so in the many genera into which
the vast army of crustaceans are classified, we find great variations
in this respect; also in the various functions which the pair of limbs
or otherwise modified appendages that spring from each segment is
called upon to play.
Under the carapace of the Great Crab are gathered together no less than
fourteen segments, nine belonging to the head and bearing appendages
transformed into eyes, antennæ, jaws, etc.; whilst five belong to
the trunk and bear the great _chelæ_ and the four pairs of walking
limbs. The remaining six segments belong to the tail (_pleon_), and in
the crabs are folded over under the united head and trunk. Among the
different groups of crustacea we shall find the widest variations in
the arrangements of these parts; even in different genera of crabs is
this so, as we shall see before we have left the long drang. “Glancing
along the whole line of limbs, as the outgrowths from the segments
have some right to be called, twenty pairs in number, we find them
successively devoted to seeing, feeling, and otherwise perceiving,
feeding, and presumably tasting, grasping and striking, walking
and digging, swimming and leaping. But although the order in which
they act may thus be generally stated, there is not unfrequently a
transfer of function from one part of the line to another. The feelers
may be employed to assist in swimming or climbing or clasping. The
mouth-organs of one group are the grasping weapons of another. The
walking legs of one set are elsewhere adapted for swimming. There are
also other functions conjugal or maternal, in which the swimming legs
or the walking legs may take part, while the breathing apparatus,
simple or complicated, may be connected with the mouth-organs or
limbs of the trunk or both, or else with the swimming organs of the
tail-part, commonly called the pleon.”--(_Stebbing._[4])
[4] History of Recent Crustacea: International Scientific Series, 1893.
What may be called the personal or life-history of the Great Crab
is a scientific romance. Once upon a time there was a grotesque sea
monster--as big as the head of a good-sized pin--that resembled in
a small way a German soldier’s spiked helmet, with a couple of huge
eyes in front of it, a long jointed tail behind it, and a few bristles
around its edge. This creature naturalists recognised as a distinct
species, to which they gave the name _Zoea taurus_. It was first
taken from the sea by a Dutch naturalist, one Martin Slabber, in the
year 1768, but his account was not published until ten years later,
whereupon Bose created a new genus to receive the little oddity. Then
there was another sea creature, not much larger, but having a distant
resemblance to a lobster, and for this form Leach founded his genus
Megalopa. Now it chanced that an Irish naturalist, Mr. J. Vaughan
Thompson, nearly fifty years later, thought he would like to verify
Slabber’s observations, and he searched for the supposed-rare _Zoea_,
and found it in profusion. He watched its progress in life, and lo!
he beheld _Zoea_ cast its skin and became at once a _Megalopa_. This
was sufficiently startling, when the best authorities had agreed that
the Crustacea went through no metamorphoses whatever; but continuing
to watch and observe, Megalopa was found at its next moult to assume
an undoubted crab-shape, and its progress thereafter revealed what has
ever since remained one of the most important facts of crustaceology,
that no such _species_ as _Zoea_ and _Megalopa_ exist, but that these
_forms_ are mere stages in the development of a crab.
As the crab grows and gets too large for its shell, the difficulty of
stretching or otherwise increasing the capacity of such a strong-box
arises. It cannot be met as in the case of mollusks, by the simple but
sufficient method of increasing the length and breadth of the shell by
adding new shelly matter to the edge; because the principal part of
the crab’s internal machinery is in that part of his shell that has no
proper edge. There is no help for it--he must do as man does when his
garments get too small to accommodate his growing body and lengthening
limbs: he gets a new suit. But a glance at his armour-plated condition
would suggest that the most difficult part of the business would be,
how to get out of the old suit! It might not be such a hopeless task
if his limbs were straight and of equal thickness throughout; but in
every case the joints are very much narrower than the rest of the limb.
Yet, in spite of this difficulty, by the shrinking of the body and its
limbs, and by the dissolution of partnership between the upper and
lower crusts, the crab, clad in a kind of parchment suit, comes clean
out, and leaves his old clothes intact, even to the coverings of the
eyes, the antennæ, and the old jaws and mouth-fittings. When the crab
emerges from his old home, he is, strange to say, much bigger than that
empty presentment of himself, and you might as well attempt to put back
the chick into the eggshell it has just vacated as to squeeze the soft
crab into his old husk.
Very probably my reader will be so fortunate in some of his captures
as to take a specimen that is on the eve of casting his shell. He may
see, as I have several times seen, the whole process, and be rewarded
with a beautifully clean cabinet specimen of the crab’s shell, perfect
in every part. It only requires careful rinsing in _fresh_ water, and
drying on a blotting pad away from the sun or heat, and is then ready
to label and put away.
Many human creatures when they chance to get a new “rig-out”--to use
a nautical expression--are only too anxious to appear in public, that
the cut and colour and pattern of the garments may be admired, and the
wearer--if of the fair sex--envied; but our crab’s paramount desire
is to get into a deep dark hole in the rock, or under a stone, and
hide himself. It is not modesty or shame that thus impels him to hide
the newness of his coat, but the knowledge that he is a wee bit soft,
and too new to meet his own brother, who would instantly improve the
occasion by eating him. He would not like his own brother to be guilty
of the hideous sins of fratricide and cannibalism at one gulp, and he
feels it his duty as his brother’s keeper to put temptation out of his
way by seeking seclusion, until the new crust has set firm and hard.
Here, in this drang, you may frequently find a soft crab in a hole,
awaiting the hardening process; you may as frequently find a hardened
one, or a lobster. They are, in fact, generally of a retiring
disposition, except when looking for breakfast. Then they quit their
holes and cavernous recesses, and come out on the open rocky bottom
where the crabber has dropped his row of “pots,” each with something
high and “gamey” skewered within. Of such a full bouquet is this
bait--delicious to the olfactory apparatus of the crab--that he scents
it from afar, and rapidly makes a one-sided progress to the string of
pots. There, within, are the lumps of delight in the shape of split
wrasse, and the osier bars of the pot are so conveniently arranged
that he can easily ascend to the top, and more easily descend to the
interior through the tubular opening. The prevailing notion is that
these pots are so constructed that it is well-nigh impossible for a
crab to get out again; but this is not so, and the fishermen know they
must go round every morning whilst the crab or lobster is still at
breakfast on the savoury viands they have provided, and haul their pots
before he has thoughts of finding the way out. Improved pots have been
invented, from which it is impossible for a crab or lobster to escape,
but the fisherman is extremely conservative, and sticks religiously to
the ways and means of his father’s great-grandfather.
Having taken his captures from the pots and thrown them into the bottom
of his boat, the fisherman rows with them to a protected area of
deep water near the shore, in which each of the crabbers keeps his own
store-pot or _hully_, and hauling his own particular hully, puts his
new captures in. This he will continue to do perhaps till the end of
the week, or until the merchant comes round with his boat to buy.
Now, having spent so much time over _Cancer pagurus_, we must leave
him, and pay some brief attention to other members of his family--of
small concern in the crabber’s eyes, but of equal interest to the
student of nature. Under the overhanging masses of _Fucus_ that drape
the rocks, in the smaller holes of those rocks and among the stones on
the floor of the drang, we are bound to meet with innumerable specimens
of two crabs that possess no English name. It is true that if you ask
the boys of the place whom you will find at times among the rocks (and
they are the most reliable of local informants on such matters), they
will tell you, with a flavour of contempt for the crabs, that these
are “devil crabs;” but later on you will find that this term is not
specific but generic, for they apply it to several species that are
worthless in their eyes. In a similar mood, the adult fisherman will
tell you they (and a number of others) are “Zebedees or devil crabs.”
Well, Dr. Leach, who founded the genus in 1813, would probably have
called it yellow-crab in the vernacular, for he dubbed it _Xantho_,
in scientific language, from the Greek _Xanthos_, yellow. Many of us
are more or less colour-blind, and should therefore be careful to
abstain from dogmatism in relation to tints, but I should certainly not
describe either of the British species of _Xantho_ as being yellow,
although some specimens of _X. hydrophilus_ are certainly yellow_ish_.
[Illustration: ZEBEDEE (XANTHO INCISUS).]
_Xantho hydrophilus_ is rather an odd, clumsy-looking creature, owing
to the want of proportion between his trunk and the large pincer-claws.
The carapace is peculiarly wrinkled, and the margin on the outside
of the eye on each side (_latero-anterior_) is marked by four stout
triangular teeth. The four pairs of smaller legs (2 to 5) have a row
of fine hairs along the upper edge of each joint; and the fingers of
the pincer-claws are brown, the moveable one being also grooved on the
upper surface. Colour yellowish-brown with darker markings.
_Xantho incisus_ is very like the last, and some specimens will prove
difficult to determine with satisfaction. The description of the
carapace and its toothed margin will apply equally to either species;
but the distinctive characters of this as compared with the last are
that (1) the fingers of the pincer-claws are _black_, (2) that they
are _not_ grooved, (3) the second to fifth pairs of legs instead of
having the fringe of hairs all along their upper margin have only the
third (or longest) joint of each leg so decorated. The second and third
points are, I believe, reliable--the first is not. I have seen many
specimens with the fingers of a paler brown even than the general hue
of the big claws, and have such a specimen alive before me as I write.
[Illustration: HAIRY-CRAB.]
In the course of our stone-turning we are likely to come upon a little
purplish-brown crab, about an inch across the carapace, and bristling
all over with hairs and spines. It is known to the naturalist as
_Pilumnus hirtellus_, but none of the writers on crabs appears to
have troubled about a popular name for it, so it is incumbent upon me
to supply the deficiency. For the purpose of communication with my
readers, I therefore dub _Pilumnus hirtellus_ with the nickname or
alias of Hairy-Crab. The front of the carapace is cut up into a number
of teeth much sharper than those of _Xantho_; in fact, in comparison
with those, these of the Hairy-crab are spines. One of these spines
protects the orbit of the eye, and there are four others on each side
between it and the base of the pincer-claws. The pincer-claws have
a very robust appearance in comparison with the size of the trunk,
being thick and rounded; one is usually larger than its fellow, but
it may be either the right or the left. The smaller of the two is
covered with tubercles on the upper parts, the larger is smooth. The
smaller legs are very hairy indeed, and similar hairs are scattered
over the carapace among the short down with which it is covered. It is
common all along the Southern and Western coasts of England and around
Ireland, under stones at low-water, though by no means so abundant
as _Xantho_, and others we have to mention. Bell, in his “History of
Stalk-eyed Crustacea,” almost seems to question Dr. Leach’s statement
that it is found at low tide mark, for he adds, “those which I have
obtained have been from deep water.” Dr. Leach, however, was quite
correct in his statement, and Bell could easily have substantiated it,
as we have done.
We shall not be long at our work before we meet with far too many
examples of the Common Shore Crab, Green Crab or Harbour Crab
(_Carcinus mænas_); young specimens of which will scuttle away sideways
with marvellous alacrity, but bigger examples will at once put up their
heavy hands and challenge us to fight. Everybody that has been to the
sea-shore knows this crab, for even if entirely void of curiosity as
to the wonders of the shore, _Carcinus mænas_ will not be ignored.
Whether the shore be sandy or rocky, or of that nondescript character
that pertains to many harbours, a mixture of sand, stones, and domestic
rubbish, this crab will be seen strolling along at a little distance
from the water. All know its mottled greeny-yellowy-brown back, and the
strength of its sharp nippers! There is only this one member of the
genus, so that there is little danger of confusing it with its nearest
relations. It most closely resembles certain of the swimming-crabs
(_Portunus_), to be described hereafter, but may be readily separated
from them by glancing at the terminal joint of the last pair of feet.
In _Portunus_ this is flattened out as though it had been beaten on an
anvil until it was very broad and very thin, to serve as a swimming
plate. In _Carcinus_, though the smaller legs are obviously compressed,
this last joint of all is stout and runs off to a rounded point, more
suited for obtaining a good hold of a sandy bottom than for swimming.
We shall find it frequently under both weeds and stones. It is an
omnivorous feeder, accepting fish, flesh, or fowl; stealing bait from
the fisherman’s lines and from his crab-pots, disfiguring the fish
which has been already caught on spillers, and, worse than all, causing
great havoc among the young oysters that have been laid down in the
beds, by eating them, shell and all. They are said to form an important
article of food along the shores of the Adriatic, and they were at one
time not unknown in the London markets. Leach says that in his time
(early in the century), immense quantities were eaten by the London
poor. Whether there is any considerable trade of this kind now I do
not know; but I remember how more than thirty years ago I considered
them very sweet and toothsome, and used to go as a boy to buy them,
all alive, of an old woman in one of that intricate maze of courts and
alleys that then existed where now the Royal Courts of Justice stand.
I think they were sold at about eight or ten for a penny. Had they not
been sold alive I should probably never have desired to have them.
[Illustration: VELVET FIDDLER.]
When throwing aside the heavy bunches of _Fucus_ that hang over the
rocks, in order that we may see their surfaces, we shall catch sight
of a more pugnacious crab even than _Carcinus_, leaping, rather than
running sideways, with such rapidity that we need to be smart to catch
it. Aye, and we need to have a little nerve, or the Velvet Fiddler
will alarm us into letting him pass into the oblivion of the seaweed
jungle, or one of those rock-crevices which always seem to be in the
right place to afford sanctuary to a poor hunted crab. Most crabs
are so flattened that these cracks seem specially provided for them,
whereas the evolutionist will tell you it is the rock-haunting crabs
that have become specially adapted to find salvation in these asylums.
This is the crab we alluded to especially when speaking of the
likeness between the swimming-crabs (_Portunus_) and the Shore Crab.
The Velvet Fiddler (_Portunus puber_) is one of the swimming-crabs;
this may easily be seen on reference to the hindmost pair of legs,
as already indicated. The Velvet Fiddler gets the two words of his
queer name from two distinct characters. He is clad in a dingy suit of
velveteen, which appears to be much the worse for wear--rusty, and in
places the nap is worn right off, probably by too much squeezing into
tight places in the rocks. On his limbs the velveteen is marked in
such definite patterns, that we feel inclined to abandon the hard-wear
theory, and to fall back upon one of natural artistic adornment. He is
really a very fine fellow; his legs being covered on the upper sides
with this velvet pile, with the exception of certain longitudinal
raised lines of polished blue-black. The square-looking back of the
carapace has a similar smooth raised border, with two raised lines of
the same character below it. Then all the smaller legs have the longest
joint fringed along the upper edge, but the hindmost pair in addition
have a close broad band of stiff feather-like fringe standing out
all round the three last joints. The last two of these are flattened
out to such an extremity of thinness that there seems to be no room
for living flesh within. The pincer-claws are not so heavy or robust
as those of the species we have already considered. They are more
uniform in thickness, more elegant in their slim tapering, so that the
members of this genus are often called Lady-crabs. The upper surface
is velvety, picked out here and there with blue, and the hand, with
its fixed nipper, is decorated below with white and blue tubercles.
The moveable nipper is finely ridged, and both of them have a fine
row of teeth. Then these pincer-claws are well-armed with long sharp
spines; the _antero-lateral_ margins of the carapace are finished off
with five sharp curved spines on each side, and the space between the
eye-orbits are similarly protected, but with thinner, straight spines.
The large round eyes are a pair of gleaming rubies, and the tough skin
that hinges the joints of the limbs together is of the same hue as the
eyes. Such is the appearance of the living Velvet Fiddler; the museum
specimens lack much of his brightness and beauty.
The name of Fiddler has been given to him, according to Mr. Gosse,
“because the see-saw motion of the bent and flattened joints of the
oar-feet is so much like that of a fiddler’s elbow.” You will, I am
sure, agree that this is a satisfactory explanation when you see the
Velvet Fiddler flinging these feet about in a perfectly unnecessary,
and ineffectual manner, considering that he is out of water. When
we disturb him during our exploration of the drang, he puts up
his pincer-claws in similar fashion to the tactics adopted by the
Shore Crab; but we are not to be alarmed in that manner. Pretending
to hit him between the eyes with one hand, we slip the other behind
him, and catch the longest part of his carapace between our finger and
thumb, and his kicks and threats are thrown away.
There are seven other species of Swimming-crabs belonging to this
genus, _Portunus_, found in British waters, but as they all inhabit
deep water, and can be obtained only with the dredge, or by arrangement
with the crabbers, who regretfully find them in their pots, they are
not likely to thrust themselves on the notice of the shore-naturalist.
Gazing into the rock-pools, an observer who was acquainted with
molluscan life, but not with the Crustacea, would be astonished at the
marvellous rate at which winkles, dog-whelks, tops, and other shells
move over the bottom; but if he lifted one of these he would discover
that the builder of the house had given up possession, and a tenant had
taken it for a term. This tenant is one or other of a dozen species
of crabs known indiscriminately to the great British Public as _the_
Hermit Crab or Soldier Crab. The fact that it shuts itself up in a
solitary cell is sufficient to account for its name of Hermit-crab; and
a strong tendency to wage war upon a fellow crab, who may live in a
slightly larger shell, is probably the reason for its military name.
The Hermit-crabs are among the curiosities of crab life--though for
the matter of that, so are all crabs. If there were but one species,
we could say it was singular in the fact that the carapace is reduced
to the smallest proportions, and the greater part of the crab’s body
without a shell of its own secretion. Nature has been unkind to it in
this respect, so the first thought or prompting in the baby Hermit
is to look around for a deserted gasteropod-shell. It must be an
exceedingly small one to fit him, but he will find plenty such. It has
been a matter for considerable debate whether the Hermit is content
with an abandoned shell, of which the builder is dead, or whether he
first murders and eats the original owner, and then takes possession
of his victim’s real estate. It is remarkable that naturalists should
raise such a question, for anyone who has had any acquaintance with
mollusks must know that if a Hermit-crab were to kill, say a Purple, a
Top, or a Winkle, he would not be able to get the dead body cleaned out
of the shell until putrescence had loosened the muscular attachment.
The Hermit could not wait for this process, and therefore I imagine
this theory must stand aside until observers have actually seen
the crabs in a state of nature forcibly ejecting the mollusk, and
appropriating its shell. But it is pretty certain that the Hermits do
rob each other of desirable shells, not always with good judgment.
A Hermit in my possession lived in a large Top-shell, but coveted a
smaller, though large Winkle-shell, which was inhabited by a brother
Hermit. For about a week these two were dodging and chasing each other,
but to no purpose, for each is powerless to make any impression when
the other suddenly shuts himself in his shell with a snap, leaving only
the tips of his claws blocking the entrance. However, by some means he
got his brother ejected, and eaten by a Shanny; he quitting his own
commodious Top-shell and putting on the Winkle-shell. He was evidently
trying hard to persuade himself that it was a splendid fit and most
becoming; but the whole business was absurd. The shell was so small
that it did not protect his soft parts, and in case of danger he could
not defend himself from an attack in the rear. To add to his troubles
he cast his natural shell, and was, of course, much larger than before.
For a day or two he still pretended that he lived in a sufficiently
roomy house; then I suppose the pressure on his abdomen became awkward
at dinner time, for he publicly owned up that he had committed an error
of judgment, quitted the Winkle-shell, and resumed possession of his
old top-coat, though this necessitated another murder. After he had
vacated it a much smaller individual took possession, but as he fitted
very loosely it was no very difficult matter for the previous owner to
have him out “by the scruff of his neck,” and give him his quietus.
The most familiar of the Hermits is _Eupagurus bernhardus_, the Common
Hermit-crab, but we are not likely to find full-grown individuals,
which keep out in deep water. When full grown, they are about five
inches long, and house themselves in large Whelk-shells. The characters
by which this species may be distinguished are: the right pincer-claw
(_cheliped_) is usually much larger than the left, and the plentiful
granulations of its surface are almost large enough to be described
as tubercles; the last joints of the second and third pairs of legs
are edged on the upper side with spiny teeth, and they are a wee bit
twisted.
Prideaux’s Hermit-crab (_Eupagurus prideaux_), is so-called because
Dr. Leach, who first identified it as a species distinct from _E.
bernhardus_, received it from his friend Prideaux, who had taken large
numbers of it in Plymouth Sound. The granulations of the pincer-claws
are much smaller than in _bernhardus_, and whereas the next joint
to the pincers in the latter species has its inner margin decorated
with a row of spines, those in _prideaux_ are innocent tubercles.
Then, again, the second and third pairs of legs are nearly smooth,
and their last joints have no twist, but instead have a groove
carved in each side; the eye-stalks are stouter and the inner antennæ
longer than in the Common species. It does not attain such large
proportions as _bernhardus_. An interesting point in the natural
history of _prideaux_, is the friendly relations subsisting between it
and a peculiar species of anemone--the so-called Cloaklet (_Adamsia
palliata_)--which attaches itself to the shell serving as the Hermit’s
cell, and spreads its base out in two lobes, that almost encircle the
mouth of the shell. There is no doubt that this _commensalism_, as such
alliances are called by naturalists, is of advantage to both parties to
it: the anemone is thus brought into contact with food at the Hermit’s
own table, so-to-speak, and the crab may be in turn protected from the
cavernous jaws of fishes, whose gorge rises at the nauseous odour of
all anemones. Several such alliances are known in connection with other
species of Hermits.
[Illustration: THE HERMIT-CRAB AND THE CLOAKLET ANEMONE.]
To return to our overhauling of stones: this should be done with care,
especially when we are dealing with large masses. I have, when serving
my apprenticeship at this kind of work, years ago, had the misfortune,
on more than one occasion, to so miscalculate the weight and shape of a
large stone, that it has fallen with greater force and in a different
direction from that expected--and my toes have been on the spot where
it fell! But apart from such accidents, the stone must be turned
sharply, or the queer creatures which Nature has specially contrived
for living beneath it, will vanish into holes, under other stones, in
the sand or mud, or in some other manner.
[Illustration:
SCALY SQUAT-LOBSTER. BROAD-CLAW.
]
Among those that require a sharp eye to see them is the Hairy Porcelain
Crab, Shaggy Flat-crab, or Broad-claw (_Porcellana platycheles_).
Here is his portrait, but it is only fair to the reader I should
explain that, like many other portraits, it was taken after the
subject of it had been carefully washed and brushed up. _Platycheles_
is a ragamuffin, a crustacean mud-lark. There is none other like him
in the whole range of British crab life, though several are fond of
dressing themselves up in a variety of living rubbish; but they do
not get themselves so bedaubed with mud on a coast where mud has to be
searched for if wanted. He has really made it one of the objects of
his life to collect that mud, particle by particle, and entangle it in
the luxuriant crop of hair with which he is covered. He is a little
fellow--only measuring about half an inch from back to front edges of
the carapace--and I suppose, were he built upon the same plan as other
crabs, he would be smaller, if only the same quantity of material were
to be allowed; for he is flattened out, and looks as though he had at
one time formed part of a travelling show and the fat woman had sat
upon him. His body is flat, but his pincer-claws are flatter, and the
area of each of the latter is equal to that of his carapace; they are
enormous. And yet, if he had the sense to keep still when the stone is
overturned, you would probably fail to see him; he sits so tightly,
and presses the cleaner side of him to the stone. But he has that
fatal _crabbiness_, the desire to fight, and whilst he is sidling off
somewhere, he thinks he may as well give you a nip, and he puts up one
of his massive-looking pincers, and grips your finger with spirit.
With your other hand you grip the offending pincer, and say, “Aha! my
friend, you’ve caught a Tartar this time; let go!” He does, but instead
of loosing his hold on your finger, he just touches a spring or some
other mechanism, and separates his claw from his body without any
compunction whatever, whilst his other claws and his body go sliddering
off beneath the stone again.
If you catch your Broad-claw young, you will find that his upper
surfaces are of a ruddy-brown tint, with hair to match, but when he has
got this well filled up with filth, he might pass for a daub of mud.
Hold him over on his back, if you can, and you will understand why he
is called Porcelain crab. He is smooth and comparatively clean beneath,
and his under surface is of a creamy-white colour.
Broad-claw has an equally odd-looking relative, the Minute Porcelain
Crab (_Porcellana longicornis_), which really belongs to deeper waters
than our researches at present extend to, but one or two can usually
be found under, or among, the stones at extreme low tide. Its colour
is red, and its carapace comes very near to being circular. It has not
that depressed appearance that makes you pity _platycheles_ for having
to support such heavy stones upon his back; in truth, the circularity
of the carapace, its convexity, and the fact that it has some depth as
well as breadth, makes it appear almost rotund. Its larger pincer-claw
is almost three times the length of the carapace; the other about
one-third less, and not nearly so thick. They are both rugged in
character, and convex, the larger being slightly keeled on top, and
the lesser strongly keeled and grooved. The antennæ are very long, a
circumstance to which the creature owes its second name. There is very
little hair about this species, and consequently he is able to keep
himself clean and neat.
In close alliance with the Porcelain-crabs is a group popularly known
(as far as they are known at all, which is but slightly) as Squat
Lobsters. They are not lobsters however, though the long slender
pincers, the elongated carapace, and the lobster-like tail all
contribute to the likeness. The most plentiful species is that figured
on page 148, with Broad-claw, viz.:--
The Scaly Squat-lobster (_Galathea squamifera_), which we shall find
freely under the stones at very low-water in our drang. He is a very
lively fellow, who objects to too much publicity, and is very anxious
to get into a hole or under another stone the moment you lift the roof
off his former retreat. He shoots backwards in true lobster fashion,
his pincers held straight out in front. If, however, you interfere with
his retrograde movement, the nippers will not be trailed uselessly,
but raised and brought into action. Like Broad-claw, he does not set
great store by a limb or two, and will willingly part with several as
the price of liberty. In colour, _squamifera_ is very dark olive, the
carapace covered with waved lines across it, said lines being evenly
fringed with short hairs. Similarly fringed scales occur plentifully
over all the legs. The carapace begins in front, with a distinct beak,
and an awful array of fixed bayonets. The first of these is a stout
sharp spine in the very front, and behind it on either side just above
the eyes is a series of four similar spines slightly curved, of which
the first is the largest, and the fourth very short. Along each side
of the carapace is a closely-set row of spines, and the outer edge of
the “hand” is protected in a like manner. The next three limbs have
smaller spines upon their upper margin, and of larger size, on what
might, from its apparent position, be popularly regarded as the knee.
All these spines, wherever fixed, agree in having red points. But
these particulars are not sufficient by themselves to distinguish this
species from certain of its congeners, and I am compelled to ask my
readers to enter into some minute, and I fear to them, tedious details
of description. Of the various appendages to the segments comprised
in the head of these crustaceans, some constitute the eyes, antennæ,
and jaws. Outside the jaws, and immediately between the pincer-claws
of _squamifera_, is a pair of appendages called the third pair of
maxillipeds or footjaws, with long hairy fringes to the extremities.
Study these carefully, for from these we can tell at once which of
three species we are looking at. Each of these mouth-organs, like the
larger legs, is made up of seven joints; but it is not always easy to
reckon these up from the base, because sometimes a joint is hidden or
coalesces with another. If now we commence at the other end, calling
the top-joint No. 7, and reckoning backwards, we shall have less
difficulty. To save further description, and to make easy of reference,
I have drawn up a table of distinguishing features for the British
species of Galathea:--
{ Third footjaws }
{ (_maxillipeds_) with }
Specimens having branch { 3rd joint shorter than 4th } _squamifera_
(_epipod_) from basal { 3rd joint longer than 2nd }
joint of pincer-legs {
and two next pairs { 3rd joint equal to 4th. } _nexa_
of legs { 3rd joint shorter than 2nd }
{
{ 3rd joint longer than 4th } _dispersa_
Branch (_epipod_) from { } _intermedia_
pincer-legs _only_ { }
No epipods from either { 2nd joint longer than 3rd } _strigosa_
pair of legs { }
The Spinous Squat-lobster (_Galathea strigosa_) has spines on his hands
along both the inner and the outer margins; and the antennæ are so long
that if extended over the back they will reach for some distance beyond
the tail. Its colour is inclined to red, with spots and lines of blue.
These are the only two we are _likely_ to find in our stone-turning,
and even _strigosa_ appears to be more at home in deeper water.
According to Couch and Spence-Bate, _dispersa_ is the commonest form in
Cornwall below the low-water mark. _Nexa_ is also a deep-water species.
At extreme low water (spring-tides) one may be so fortunate among these
rocks to come across a stray lobster or two. Just outside you can see
the corks which mark the ends of the long series of lobster pots that
are put down to catch them, so that it is not very far for them to
stray up to this level. I think my readers could be trusted to know
the Lobster (_Astacus gammarus_) if they saw it, without bothering
them with a description? Probably they would not be expecting to see a
creature with a coat of the same colour as the uniform of a grenadier
guard, instead of blue-black relieved on the underside by dull orange.
They may also be trusted to know the Spiny Lobster, Crawfish or Greek
(_Palinurus vulgaris_), with its very horrid carapace of purplish
brown, its lack of heavy pincer-legs, its red-tinted white legs, and
its long, thick and strong antennæ. If you do not come across either of
these at low-water, you may see them when the crabbers bring in their
catches. Their boats should be watched as they come in each morning,
for you can frequently pick up deep-water specimens of _Echini_,
spider-crabs, and so forth, that have dropped out of the crab-pots into
the boat.
[Illustration: PRICKLY SPIDER-CRAB.]
On our south-western shores you will see, brought in by the crabbers,
or occasionally at liberty among the rocks, a rough, long-legged fellow
called the Prickly Spider-crab, Corwich, or Gabrick (_Maia squinado_),
with a convex carapace of oval form, the broadest part behind. His
pincer-legs are but little thicker, though much longer, than the
others. On that account he is not greatly esteemed as merchandise,
but his flesh is far sweeter than that of the Great Crab. He is a
creature of slow and languid habit, who takes as much pains with the
“get-up” of his carapace as a lady does with her hair or her bonnet.
His notion is to make it look like a rough piece of rock, with its
characteristic flora and fauna, and to this end he takes cuttings of
plants, sponges, ascidians, and anemones, and giving them a lick with
his lips, as though they were postage stamps, he carefully sticks them
in the valleys between the spines and tubercles on his back, adjusting
them by means of his conveniently long arms. The seeker after zoophytic
treasures might look in many a worse place for them than on the
Gabrick’s back.
We have now done as much as possible with the crabs of the rocky shore,
and must shift our ground for a while to the flat sands that run out
from the upper part of the bay, and taking advantage of the very lowest
tides, must go, armed with trowel or spade, to dig in the treacherous
sands. Many things we may find other than those we came specially to
seek, and those we specially want just now may not come to light; still
it is in the sand we shall find the Masked-Crab and the Angular-Crab,
if they occur in the district.
[Illustration: THE MASKED-CRAB (MALE).]
The Masked-crab (_Corystes cassivelaunus_) has a carapace that is much
longer than it is broad, almost elliptical in outline, and so marked
with depressions that some specimens present a remarkable likeness
to a human face, more especially so if the crab is held in a way
that will accentuate the prominences by casting small shadows. It is
prettily coloured with yellow and red. The male has deeper tints than
the female, and his pincer-legs are much longer than hers. Their habit
is to burrow into the sand in rather deep water, and lie buried, with
only the tips of their long antennæ at the surface. These antennæ are
furnished with a double row of hairs throughout their length, and by
placing the antennæ so close together that these hairs interlock, a
tube is formed through which the crab can draw in the current of water
necessary for respiration. After storms, great numbers of this crab are
sometimes cast up on the shore, dead.
Another crab of singular aspect is the Angular-crab (_Gonoplax
rhomboides_), so-called on account of the many sharp angles of the
flesh-tinted carapace. Its pincer-legs look as though they had been
drawn out when the animal was soft, for in the adult male they are
quite four times the length of the carapace--in the female and young
male they are much less. Another distinction of the sexes will be found
in the colour of the moveable finger of the pincers, which is black
in the male only. The eyes are mounted on such long stalks that they
reach nearly to the sides of the carapace, which run out into a long
sharp spine at each front corner for the protection of the eyes. These
are mounted very much like the eyes of the Racer-crab (_Ocypoda_) of
other lands, and they are used for a similar purpose. The footstalks
are erected so that the crab can see over a wider extent of territory,
and behind as well as before. They appear to live in excavations in the
mud on our southern and western coasts. They are much esteemed as food
by various kinds of fish, and many specimens have been taken from the
stomach of the cod particularly.
[Illustration:
NUT-CRAB. ANGULAR-CRAB.
]
If it be desired to keep living crabs for the purpose of observing
them, a shallow vessel will be found the best; or at least, a vessel in
which they can easily get into shallow water. Provision should always
be made whereby a crab can climb right out of the water, yet so that
he cannot get out of the vessel; otherwise he will wander all over the
house, and either get stepped upon, or get dried up in some obscure
corner. It must be remembered that the crab consumes much oxygen, and
if specimens of any size are put into tanks containing more delicate
creatures, much harm may result. It should also be borne in mind that
they are of ravenous and omnivorous appetite, and your choice specimens
of soft-bodied creatures will not be held sacred by the crabs. We
should therefore advise a separate receptacle for crustaceans; and
some of the smaller, more delicate kinds, must be kept each in their
own vessels. The smaller species will probably be able to pick up
sufficient food from the minute animal and vegetable life of your
tanks, but the large ones will require to have food specially provided
for them. Small pieces of fish will be found the most convenient for
this purpose, and it will be more highly appreciated if it be not too
fresh. Like the slum-boy who could not relish farmhouse eggs because
they were deficient in flavour, the crab prefers his food to be kept
for a time.