Winnipeg appears quite alive with these fish in the month of June; and
some families of the natives resort thither at that time to spear them
with a harpoon, or grapple them with a strong hook tied to a pole.
Notwithstanding the great muscular power of the Sturgeon, it is timid;
and Dr. Richardson saw one so frightened at the paddling of a canoe,
that it ran its nose into a muddy bank, and was taken by a _voyageur_,
who leaped upon its back.
In Colombia River, a small species of Sturgeon attains eleven feet in
length, and a weight of six hundred pounds.[20] It is caught as high up
as Fort Colville, notwithstanding the numerous intervening cataracts and
rapids which seem to be insuperable barriers to a fish so sluggish in
its movements.
The Sturgeon is styled a Royal Fish in England, because, by a statute
of Edward II. it is enacted, "the King shall have Sturgeon taken in the
sea, or elsewhere, within the realm."
FOOTNOTES:
[18] "The Naturalist in Vancouver Island and British Columbia." By John
Keast Lord, F.Z.S., Naturalist to the British North American Boundary
Commission.
[19] The Petrel is similarly used in the Faroe Islands. (See _ante_, p.
234.) It may, therefore, be called the Candle Bird.
[20] Dr. Richardson. The _Huro_ is reported by Pallas to attain a weight
of nearly three thousand pounds, and a length exceeding thirty feet.
THE TREE-CLIMBING CRAB.
The transition from the ordinary mode of the locomotion of fishes by
swimming to that of climbing has been ably illustrated by the Rev. Dr.
Buckland, who showed, in a communication to the Ashmolean Society, in
1843, that the fins in certain genera perform the functions of feet
and wings. Thus, "fishing-frogs" have the fins converted into feet, or
paddles, by means of which they have the power of crawling or hopping
on sand and mud; and another species can live three days out of the
water, and walk upon dry land. The climbing perch of the Indian rivers
is known to live a long time in the air, and to climb up the stems of
palm-trees in pursuit of flies, by means of spinous projections on its
gill-covers. Fishes of the _silurus_ family have a bony enlargement of
the first ray of the pectoral fin, which is also armed with spines;
and this is not only an offensive and defensive weapon, but enables
the fish to walk along the bottom of the fresh waters which it
inhabits. The flying-fishes are notorious examples of the conversion
of fins into an organ of movement in the air. M. Deslongchamps has
published, in the "Transactions of the Linnæan Society of Normandy,"
1842, a curious account of the movements of the gurnard at the bottom of
the sea. In 1839, he observed these movements in one of the artificial
fishing-ponds, or fishing-traps, surrounded by nets, on the shore of
Normandy. He saw a score of gurnards closing their fins against their
sides, like the wing of a fly in repose, and without any movement of
their tails, walking along the bottom by means of six free rays, three
on each pectoral fin, which they placed successively on the ground.
They moved rapidly forwards, backwards, to the right and left, groping
in all directions with these rays, as if in search of small crabs.
Their great heads and bodies seemed to throw hardly any weight on the
slender rays, or feet, being suspended in water, and having their weight
further diminished by their swimming-bladder. During these movements the
gurnards resembled insects moving along the sand. When M. Deslongchamps
moved in the water, the fish swam away rapidly to the extremity of the
pond; when he stood still, they resumed their ambulatory movement, and
came between his legs. On dissection, we find these three anterior rays
of the pectoral fins to be supported each with strong muscular apparatus
to direct their movements, apart from the muscles that are connected
with the smaller rays of the pectoral fin.
Dr. Buckland states that Miss Potts, of Chester, had sent to him a
flagstone from a coalshaft at Mostyn, bearing impressions which he
supposed to be the trackway of some fish crawling along the bottom
by means of the anterior rays of its pectoral fins. There were no
indications of feet, but only scratches, symmetrically disposed on each
side of a space that may have been covered by the body of the fish
whilst making progress, by pressing its fin-bones on the bottom. As yet,
no footsteps of reptiles, or of any animals more highly organized than
fishes, have been found in strata older than those which belong to the
new red sandstone. The abundant remains of fossil fishes, armed with
strong bony spines, and of other fishes allied to the gurnard, in strata
of the carboniferous and old red sandstone series, would lead us to
expect the frequent occurrence of impressions made by their locomotive
organs on the bottoms of the ancient waters in which they lived. Dr.
Buckland proposed to designate these petrified traces or trackways of
ancient fishes by the term of fish-tracks.
Crabs and Lobsters are strange creatures: strange in their
configurations; strange in the transmutations which they exhibit from
the egg to maturity; strange in the process they undergo of casting off,
not only their shell, but the covering of their eyes, of their long
horns, and even the lining of their tooth-furnished stomach; strange,
also, are they in their manners and habits. Many a reader, in wandering
along the sea-shore, may have disturbed little colonies of Crabs
quietly nestling in fancied security amidst banks of slimy sea-weed; and
in the nooks and recesses of the coast, the shallows, and strips of land
left dry at ebb-tide, may be seen numbers of little, or perchance large,
Crabs, some concealed in snug lurking-places, others tripping, with a
quick _side-long_ movement, over the beach, alarmed by the advance of an
unwelcome intruder. Some are exclusively tenants of the water, have feet
formed like paddles for swimming, and never venture on land; others seem
to love the air and sunshine, and enjoy an excursion, not without hopes
of finding an acceptable repast, over the oozy sands; some, equally fond
of the shore and shallow water, appropriate to themselves the shells of
periwinkles, whelks, &c., and there live in a sort of castle, which they
drag about with them on their excursions, changing it for a larger as
they increase in measure of growth. They vary in size from microscopic
animalcules to the gigantic King Crab:[21] to the former, the luminosity
of the ocean, or of the foam before the prows of vessels, is, to a
great extent, attributable, each minute creature glowing with phosphoric
light.
The Bernhard Crab has been proved to have the power of dissolving
shells, it not being unusual to find the long fusiform shells which are
inhabited by these animals with the inner lip, and the greater part of
the pillar on the inside of the mouth, destroyed, so as to render the
aperture much larger than usual. Dr. Gray is quite convinced that these
Crabs have the above power, some to a much greater degree than others.
Certain Crabs, especially in the West Indies, are almost exclusively
terrestrial, visiting the sea only at given periods, for the deposition
of their eggs. These Crabs carry in their gill-chambers sufficient water
for the purpose of respiration; they live in burrows, and traverse
considerable tracts of land in the performance of their migratory
journeys. Of these, some, as the Violet Crab, are exquisite delicacies.
Of a great Crab migration we find these details in the "Jamaica Royal
Gazette:"--In 1811 there was a very extraordinary production of Black
Crabs in the eastern part of Jamaica. In June or July the whole district
of Manchidneed was covered with countless numbers, swarming from the sea
to the mountains. Of this the writer was an eye-witness. On ascending
Over Hill from the vale of Plantain Garden River, the road appeared of a
reddish colour, as if strewed with brick-dust. It was owing to myriads
of young Black Crabs, about the size of the nail of a man's finger,
moving at a pretty quick pace, direct for the mountains. "I rode along
the coast," says the writer, "a distance of about fifteen miles, and
found it nearly the same the whole way. Returning the following day, I
found the road still covered with them, the same as the day before. How
have they been produced, and where do they come from? were questions
everybody asked, and nobody could answer. It is well known that Crabs
deposit their eggs once a year, in May; but, except on this occasion,
though living on the coast, I had never seen above a dozen young Crabs
together; and here were myriads. No unusual number of old Crabs had been
observed in that season; and it is worthy of note, that they were moving
from a rock-bound coast of inaccessible cliffs, the abode of sea-birds,
and exposed to the constant influence of the trade winds. No person, as
far as I know, ever saw the like, except on that occasion; and I have
understood that since 1811 Black Crabs have been more abundant further
in to the interior of the island than they were ever known before."
Cuvier describes the Burrowing Crab as displaying wonderful
instinct:--"The animal closes the entrance of its burrow, which is
situated near the margin of the sea, or in marshy grounds, with its
largest claw. These burrows are cylindrical, oblique, very deep, and
very close to each other; but generally each burrow is the exclusive
habitation of a single individual. The habit which these crabs have of
holding their large claw elevated in advance of the body, as if making a
sign of beckoning to some one, has obtained for them the name of Calling
Crabs. There is a species observed by Mr. Bosc in South Carolina,
which passes the three months of the winter in its retreat without
once quitting it, and which never goes to the sea except at the epoch
of egg-laying." The same observations apply to the Chevalier Crabs (so
called from the celerity with which they traverse the ground). These are
found in Africa, and along the borders of the Mediterranean.
Some Crabs, truly aquatic, as the Vaulted Crab of the Moluccas, have
the power of drawing back their limbs, and concealing them in a furrow,
which they closely fit; and thus, in imitation of a tortoise, which
retracts its feet and head within its shell, they secure themselves,
when alarmed. Other aquatic species have their limbs adapted for
clinging to weeds and other marine objects. Of these some have the
two or four hind pairs of limbs so placed as to appear to spring from
the back; they terminate in a sharp hook, by means of which the Crab
attaches itself to the valves of shells, fragments of coral, &c.,
which it draws over its body, and thus lurks in concealment. Allied,
in some respects, to the Hermit or Soldier Crabs, which tenant empty
shells, is one which, from its manners and habits, is one of the most
extraordinary of its race. The Hermit Crabs are voracious, and feed
on animal substances. The Hermit, or Bernhard Crab, is so called from
its habit of taking up its solitary residence in deserted shells, thus
seeking a protection for its tail, which is long and naked. It is found
in shells of different dimensions, and from time to time leaves its
abode, as it feels a necessity, for a more commodious dwelling. It is
said to present, on such occasions, an amusing instinct as it inserts
the tail successively into several empty shells until one is found to
fit. We learn from Professor Bell, however, that it does not always wait
until the home is vacant, but occasionally rejects the rightful occupant
with some violence. On the contrary, the Crab, or rather Lobster-Crab
(for it takes an intermediate place between them), is more delicate in
its appetite, and feeds upon fruits, to obtain which it is said to climb
up certain trees, at the feet of which it makes a burrow. This species
is the Purse Crab, or Robber Crab, of Amboyna and other islands in the
South Pacific Ocean.
"According to popular belief among the Indians," says Cuvier, "the
Robber Crab feeds on the nuts of the cocoa-tree, and it makes its
excursions during the night; its places of retreat are fissures in the
rocks, or holes in the ground." The accounts of the early writers and
travellers, as well as of the natives, were disbelieved; but their truth
has since been abundantly confirmed. MM. Quoy and Guimard assure us that
several Robber Crabs were fed by them for many months on cocoa-nuts
alone; and a specimen of this Crab was submitted to the Zoological
Society, with additional information from Mr. Cuming, in whose fine
collection from the islands of the South Pacific several specimens were
preserved. Mr. Cuming states these Crabs to be found in great numbers in
Lord Hood's Island, in the Pacific. He there frequently met with them on
the road. On being disturbed, the Crabs instantly assumed a defensive
attitude, making a loud snapping with their powerful claws, or pincers,
which continued as they retreated backwards. They climb a species of
palm to gather a small kind of cocoa-nut that grows thereon. They live
at the roots of trees, and not in the holes of rocks; and they form a
favourite food among the natives. Such is the substance of Mr. Cuming's
account. Mr. Darwin, in his "Researches in Geology and Natural History,"
saw several of these Crabs in the Keeling Islands, or Cocos Islands, in
the Indian Ocean, about 600 miles distant from the coast of Sumatra. In
these islands, of coral formation, the cocoa-nut tree is so abundant as
to appear, at first glance, to compose the whole wood of the islands.
Here the great Purse Crab is abundant. Mr. Darwin describes it as a Crab
which lives on the cocoa-nut, is common on all parts of the dry land,
and grows to a monstrous size. This Crab has its front pair of legs
terminated by very strong and heavy pincers, and the last pair by others
which are narrow and weak. It would at first be thought quite impossible
for a Crab to open a strong cocoa-nut, covered with the husk; but Mr.
Liesk assures me that he has repeatedly seen the operation effected.
The Crab begins by tearing away the husk, fibre by fibre, and always
from that end under which the three eye-holes are situated. When this
is completed the Crab commences hammering with its heavy claws on one
of these eye-holes till an opening is made. Then, turning its body, by
the aid of its posterior and narrow pair of pincers, it extracts the
white albuminous substance. I think this as curious a case as I ever
heard of, and likewise of adaptation in structure between two objects
apparently so remote from each other in the scheme of nature as a Crab
and a cocoa-nut tree. The Crab is diurnal in its habits; but it is said
to pay every night a visit to the sea for the purpose of moistening its
gills. These gills are very peculiar, and scarcely fill up more than a
tenth of the chamber in which they are placed: it doubtless acts as a
reservoir for water, to serve the Crab in its passage over the dry and
heated land. The young are hatched and live for some time on the coast;
at this period of existence we cannot suppose that cocoa-nuts form any
part of their diet; most probably soft saccharine grasses, fruits, and
certain animal matters, serve as their food until they attain a certain
size and strength.
The adult Crabs, Mr. Darwin tells us, inhabit deep burrows, which they
excavate beneath the roots of trees; and here they accumulate great
quantities of the picked fibres of the cocoa-nut husk, on which they
rest as on a bed. The Malays sometimes take advantage of the labours of
the Crab by collecting the coarse fibrous substance, and using it as
junk. These Crabs are very good to eat; moreover, under the tail of the
larger ones there is a great mass of fat, which, when melted, yields as
much as a quart bottleful of limpid oil.
The Crab's means of obtaining the cocoa-nuts have, however, been much
disputed. It is stated by some authors to crawl up the trees for the
purpose of stealing the nuts. This is doubted; though in the kind of
palm to which Mr. Cuming refers as being ascended by this Crab, the
task would be much easier. Now, Mr. Darwin states, that in the Keeling
Islands the Crab lives only on the nuts which fall to the ground. It
may thus appear that Mr. Cuming's and Mr. Darwin's respective accounts
of the _non-climbing_ of this Crab on the one side, and its _actually
climbing trees_ on the other, are contradictory. The height of the stem
of the cocoa-nut tree, its circumference, and comparative external
smoothness, would prove insurmountable, or at least very serious
obstacles, to the most greedy Crab, however large and strong it might
be. But these difficulties are by no means so formidable in the tree
specified by Mr. Cuming: this is arborescent, or bushy, with long, thin,
rigid, sword-shaped leaves, resembling those of the pineapple, usually
arranged spirally, so that they are commonly called Screw Pines. They
are of the genus _Pandanus_, a word derived from the Malay _Pandang_.
The ascent of these arborescent plants, having the stem furnished
with a rigging of cord-like roots, and bearing a multitude of firm,
long, and spirally-arranged leaves, would be by no means a work of
difficulty, as would necessarily be that of the tall feathery-topped
cocoa-tree, destitute of all available points of aid or support. Hence
the contradiction in the two accounts referred to is seeming, and not
real, and the two statements are reconciled.
To sum up, Mr. Cuming fully testifies to the Crab climbing the Screw
Pines; and he has told Professor Owen that he has actually seen the Crab
climbing the cocoa-nut tree. The Crab has been kept on cocoa-nuts for
months; and is universally reported by the natives to climb the trees at
night.
[Illustration: THE TREE-CLIMBING CRAB.]
We may here, too, observe, that fine specimens of the Climbing Crab are
to be seen in the British Museum. Here, too, arranged in cases, are
Spider Crabs; Crabs with oysters growing on their backs, thus showing
that Crabs do not shed their shells every year, or that the oyster
increases very rapidly in bulk; Oval-bodied Crabs; and Fin-footed or
Swimming Crabs. Here are also Telescope, or Long-eyed Crabs, and Land
Crabs, found in India 4,000 feet above the sea-level; another of similar
habits in the plains of the Deccan, that may be seen swarming in the
fields, some cutting and nipping the green rice-stalks, and others
waddling off backwards with sheaves bigger than themselves. To these
may be added Square-bodied Crabs, Crested Crabs; Porcelain Crabs, with
delicate, china-like shells; and Death's-head Crabs, which usually form
cases for themselves from pieces of sponge and shells.
Certain species of Crabs are remarkably tenacious of life, and have been
known to live for weeks buried, and without food. It is in the Crab
tribe that the fact of the metamorphosis of _crustacea_ has been most
distinctly perceived; a small, peculiar crustacean animal, that had
long passed for a distinct species, under the name of _Zoea_, having at
length been identified with the young of the common Crab before it had
attained its full development.
That among the Crab tribes a tree-climbing species is to be found is
certainly curious, but it is not without a parallel among fishes. Many
of the latter leave the water, some even for a long time, and perform
overland journeys, aided in their progress by the structure of their
fins. In these fishes the gills and gill-chambers are constructed for
the retention of water for a considerable time, so as to suffice for the
necessary degree of respiration. In our country, we may mention the eel,
which often voluntarily quits the river or lake, and wanders during the
night over the adjacent meadows, probably in quest of dew-worms. But the
marshes of India and China present us with fishes much more decidedly
terrestrial, and some of which were known to the ancients. Among these
are several fishes of a snake-like form: they have an elongated,
cylindrical body, and creep on land to great distances from their native
waters. The boatmen of India often keep these fishes for a long time
out of water, for the sake of diverting themselves and others by their
terrestrial movements, and children may often be seen enjoying this
sport.
Of these land-haunting fishes, the most remarkable is the tree-climber,
so called in Tranquebar. This fish inhabits India, the Indian islands,
and various parts of China, as Chusan, &c., living in marshes, and
feeding on aquatic insects, worms, &c. According to Daldorf, a Danish
gentleman, who, in 1797, communicated an account of the habits of this
fish to the Linnæan Society, it _mounts up_ the bushes or low palms
to some elevation. This gentleman states that he had himself observed
it in the act of ascending palm-trees near the marshes, and had taken
it at a height of no less than five feet, measured from the level of
the adjacent water. It effects its ascent by means of its pectoral and
under fins, aided by the action of the tail and the spines which border
the gill covers. It is by the same agency that it traverses the land.
The statement of M. Daldorf is corroborated by M. John, also a Danish
observer, to whom we are indebted for the knowledge of its name in
Tranquebar, which alludes to its arboreal proceedings.
It is true that many other naturalists who have observed the habits
of this fish in its native regions, while they concur in describing
its terrestrial journeys, and its living for a long time out of water,
either omit to mention, or mention with doubt, its reputed attempts at
_tree-climbing_.
The habits and instincts of certain Crawfishes are very extraordinary.
Thus, the _Astaci_ are migratory, and in their travels are capable of
doing much damage to dams and embankments. On the Little Genesee River
they have, within a few years, compelled the owner of a dam to rebuild
it. The former dam was built after the manner of dykes, _i.e._, with
upright posts, supporting sleepers, laid inclining up the stream. On
these were laid planks, and the planks were covered with dirt. The
_Astacus_ proceeding up the stream would burrow under the planks where
they rested on the bottom of the stream, removing bushels of dirt and
gravel in the course of a night. They travel over the dam in their
migrations, _often climbing posts_ two or three feet high to gain the
pond above.[22]
We have to add a new and eccentric variety of nature--the Pill-making
Crab, which abounds at Labuan, Singapore, and Lahore, and is described
in Mr. Collingwood's "Rambles of a Naturalist." When the tide is down,
this little creature, if stealthily watched, may be seen creeping up
a hole in the sandy shore, taking up rapidly particles of the loose
powdery sand in its claws, and depositing them in a groove beneath the
thorax. A little ball of sand, about the size of a filbert, is forthwith
projected, though whether it passes actually through the mouth is not
made clear. Pill after pill is seized with one claw, and laid aside,
until the beach is covered with these queer little pellets. This is
evidently the creature's mode of extracting particles of food from the
sand.
Mr. Collingwood also describes, as met with on the shores and waters of
the China seas, Glass Crabs, whose flat, transparent, leaf-like bodies
seem made of fine plates of mica. The dredge brings up many a rich
haul of sponges, corals, and gorgoniæ, of the most splendid colours,
certain of the sponges harbouring within their cells minute crabs of a
new genus. Between Aden and Galle the sea is of a pinkish colour, owing
to the immense accumulation of minute kinds of medusæ, in solid masses
of red jelly. Over Fiery Cross Reef, the mirror-like sea reveals, at
the depth of sixty or seventy feet, this wealth of natural treasures.
"Glorious masses of living coral strew the bottom: immense globular
madrepores--vast overhanging mushroom-shaped expansions, complicated
ramifications of interweaving branches, mingled with smaller and more
delicate species--round, finger-shaped, horn-like and umbrella-form--lie
in wondrous confusion. Here and there is a large clam-shell, wedged
in between masses of coral, the gaping, zigzag mouth covered with the
projecting mantle of the deepest Prussian blue; beds of dark purple,
long-spined Echini, and the thick black bodies of sea-cucumbers vary the
aspect of the sea bottom."[23]
FOOTNOTES: