FISHES.
Hitherto no branch of the zoology of Ceylon has been so imperfectly investigated as its Ichthyology. Little has been done in the examination and description of its fishes, especially those which frequent the rivers and inland waters. Mr. BENNETT, who was for some years employed in the Civil Service, directed his attention to the subject, and published in 1830 some portions of a projected work on the marine fishes of the island[3231], but it never proceeded beyond the description of thirty individuals. The great work of Cuvier and Valenciennes[3232] particularises about one hundred species, specimens of which were procured from Ceylon by Reynard, Leschenault and other correspondents; but of these not more than half a dozen belong to fresh water.
The fishes of the coast, as far as they have been examined, present few that are not in all probability common to the seas of Ceylon and India. A series of drawings, including upwards of six hundred species and varieties of Ceylon fish, all made from recently-captured specimens, have been submitted to Professor Huxley, and a notice of their general characteristics forms an interesting appendix to the present chapter.[3241]
Of those in ordinary use for the table the finest by far is the Seir-fish[3242], a species of Scomberoids, which is called Tora-malu by the natives. It is in size and form very similar to the salmon, to which the flesh of the female fish, notwithstanding its white colour, bears a very close resemblance both in firmness and flavour.
Mackerel, carp, whitings, mullet both red and striped, perches and soles are abundant, and a sardine (Sardinella Neohowii, Val.) frequents the southern and eastern coast in such profusion that in one instance in 1839, a gentleman who was present saw upwards of four hundred thousand taken in a haul of the nets in the little bay of Goyapanna, east of Point-de-Galle. As this vast shoal approached the shore the broken water became as smooth as if a sheet of ice had been floating below the surface.[3243]
Poisonous Fishes.—The sardine has the reputation of being poisonous at certain seasons, and accidents ascribed to eating it are recorded in all parts of the island. Whole families of fishermen who have partaken of it have died. Twelve persons in the jail of Chilaw were thus poisoned, about the year 1829; and the deaths of soldiers have repeatedly been ascribed to the same cause. It is difficult in such instances to say with certainty whether the fish were in fault; whether there was not a peculiar susceptibility in the condition of the recipients; or whether the mischief may not have been occasioned by the wilful administration of poison, or its accidental occurrence in the brass cooking vessels used by the natives. The popular belief was, however, deferred to by an order passed by the Governor in Council in February, 1824, which, after reciting that "Whereas it appears by information conveyed to the Government that at three several periods at Trincomalie, death has been the consequence to several persons from eating the fish called Sardinia during the months of January and December," enacts that it shall not be lawful in that district to catch sardines during these months, under pain of fine and imprisonment. This order is still in force, but the fishing continues notwithstanding.[3251]
Sharks.—Sharks appear on all parts of the coast, and instances continually occur of persons being seized by them whilst bathing even in the harbours of Trincomalie and Colombo. In the Gulf of Manaar they are taken for the sake of their oil, of which they yield such a quantity that "shark's oil" is a recognised export. A trade also exists in drying their fins, for which, owing to the gelatine contained in them, a ready market is found in China; whither the skin of the basking shark is also sent, to be converted, it is said, into shagreen.
Saw Fish.—The huge Pristis antiquorum[3252] infests the eastern coast of the island, where it attains a length of from twelve to fifteen feet, including the serrated rostrum from which its name is derived. This powerful weapon seems designed to compensate for the inadequacy of the ordinary maxillary teeth which are unusually small, obtuse, and insufficient to capture and kill the animals which form the food of this predatory shark. To remedy this, the fore part of the head and its cartilages are prolonged into a flattened plate, the length of which is nearly equal to one third of the whole body, its edges being armed with formidable teeth, that are never shed or renewed, but increase in size with the growth of the creature.
The Rays form a large tribe of cartilaginous fishes in which, although the skeleton is not osseous, the development of organs is so advanced that they would appear to be the highest of the class, approaching nearest to amphibians. They are easily distinguished from the sharks by their broad and flat body, the pectoral fins being expanded like wings on each side of the trunk. They are all inhabitants of the ocean, and some grow to a prodigious size. Specimens have been caught of twenty feet in breadth. These, however, are of rare occurrence, as such huge monsters usually retreat into the depths of the sea, where they are secure from the molestation of man. It is, generally speaking, only the young and the smaller species that approach the coasts, where they find a greater supply of those marine animals which form their food. The Rays have been divided into several generic groups, and the one of which a drawing (Aëtobates narinari[3271]) is given, has very marked characteristics in its produced snout, pointed and winged-like pectoral fins, and exceedingly long, flagelliform tail. The latter is armed with a strong, serrated spine, which is always broken off by the fishermen immediately on capture, under the impression that wounds inflicted by it are poisonous. Their fears, however, are utterly groundless,
as the ray has no gland for secreting any venomous fluid. The apprehension may, however, have originated in the fact that a lacerated wound such as would be produced by a serrated spine, is not unlikely to assume a serious character, under the influence of a tropical climate. The species figured on the last page is brownish-olive on the upper surface, with numerous greenish-white round spots, darkening towards the edges. The anterior annulations of the tail are black and white, the posterior entirely black. Its mouth is transverse and paved with a band of flattened teeth calculated to crush the hard shells of the animals on which it feeds. It moves slowly along the bottom in search of its food, which consists of crustacea and mollusca, and seems to be unable to catch fishes or other quickly moving animals. Specimens have been taken near Ceylon, of six feet in width. Like most deep-sea fishes, the ray has a wide geographical range, and occurs not only in all the Indian Ocean, but also in the tropical tracts of the Atlantic.
Another armed fish, renowned since the times of Ælian and Pliny for its courage in attacking the whale, and even a ship, is the sword-fish (Xiphias gladius).[3281] Like the thunny and bonito, it is an inhabitant of the deeper seas, and, though known in the Mediterranean, is chiefly confined to the tropics. The dangerous weapon with which nature has equipped it is formed by the prolongation and intertexture of the bones of the upper jaw into an exceedingly compact cylindrical protuberance, somewhat flattened at the base, but tapering to a sharp point. In strange inconsistence with its possession of so formidable an armature, the general disposition of the sword-fish is represented to be gentle and inoffensive; and although the fact of its assaults upon the whale has been incontestably established, yet the motive for such conflicts, and the causes of its enmity, are beyond conjecture. Competition for food is out of the question, as the Xiphias can find its own supplies without rivalry on the part of its gigantic antagonist; and as to converting the whale itself into food, the sword-fish, from the construction of its mouth and the small size of its teeth, is quite incapable of feeding on animals of such dimensions.
In the seas around Ceylon sword-fishes sometimes attain to the length of twenty feet, and are distinguished by the unusual height of the dorsal fin. Those both of the Atlantic and Mediterranean possess this fin in its full proportions, only during the earlier stages of their growth. Its dimensions even then are much smaller than in the Indian species; and it is a curious fact that it gradually decreases as the fish approaches to maturity; whereas in the seas around Ceylon, it retains its full size throughout the entire period of life. They raise it above the water, whilst dashing along the surface in their rapid course; and there is no reason to doubt that it occasionally acts as a sail.
The Indian species (which are provided with two long and filamentous ventral fins) have been formed into the genus Histiophorus; to which belongs the individual figured on the next page. It is distinguished from others most closely allied to it, by having the immense dorsal fin of one uniform dark violet colour; whilst in its congeners, it is spotted with blue. The fish from which the engraving has been made, was procured by Dr. Templeton, near Colombo. The species was previously known only by a single specimen captured in the Red Sea, by Rüppell, who conferred upon it the specific designation of "immaculatus."[3301]
Ælian, in his graphic account of the strange forms presented by the fishes inhabiting the seas around Ceylon, says that one in particular is so grotesque in its configuration, that no painter would venture to depict it; its main peculiarity being that it has feet or claws rather than fins.[3302] The annexed drawing[3303] may probably represent the creature to which the informants of Ælian referred. It is a cheironectes; one of a group in which the bones of the carpus form arms that support the pectoral fins, and enable these fishes to walk along the moist ground, almost like quadrupeds.
They belong to the family of Lophiads or "anglers," not unfrequent on the English coast; which conceal themselves in the mud, displaying only the erectile ray, situated on the head, which bears an excrescence on its extremity resembling a worm; by agitating which, they attract the smaller fishes, that thus become an easy prey.
On the rocks in Ceylon which are washed by the surf there are quantities of the curious little fish, Salarius alticus[3321], which possesses the faculty of darting along the surface of the water, and running up the wet stones, with the utmost ease and rapidity. By aid of the pectoral and ventral fins and gill-cases, they move across the damp sand, ascend the roots of the mangroves, and climb up the smooth face of the rocks in search of flies; adhering so securely as not to be detached by repeated assaults of the waves. These little creatures are so nimble, that it is almost impossible to lay hold of them, as they scramble to the edge, and plunge into the sea on the slightest attempt to molest them. They are from three to four inches in length, and of a dark brown colour, almost undistinguishable from the rocks they frequent.
But the most striking to the eye of a stranger are those fishes whose brilliancy of colouring has won for them the wonder even of the listless Singhalese. Some, like the Red Sea Perch (Holocentrum rubrum, Forsk) and the Great Fire Fish[3322], are of the deepest scarlet and flame colour; in others purple predominates, as in the Serranus flavo-cæruleus; in others yellow, as in the Choetodon Brownriggii[3323], and Acanthurus vittatus, of Bennett[3331], and numbers, from the lustrous green of their scales, have obtained from the natives the appropriate name of Giraway, or parrots, of which one, the Sparus Hardwickii of Bennett, is called the "Flower Parrot," from its exquisite colouring, being barred with irregular bands of blue, crimson, and purple, green, yellow, and grey, and crossed by perpendicular stripes of black.
Of these richly coloured fishes the most familiar in the Indian seas are the Pteroids. They are well known on the coast of Africa, and thence eastward to Polynesia; but they do not extend to the west coast of America, and are utterly absent from the Atlantic. The rays of the dorsal and pectoral fins are so elongated, that when specimens were first brought to Europe it was conjectured that these fishes have the faculty of flight, and hence the specific name of "volitans" But this is an error, for, owing to the deep incisions between the pectoral rays, the pteroids are wholly unable to sustain themselves in the air. They are not even bold swimmers, living close to the shore and never venturing into the deep sea. Their head is ornamented with a number of filaments and cutaneous appendages, of which one over
each eye and another at the angles of the mouth are the most conspicuous. Sharp spines project on the crown and on the side of the gill-apparatus, as in the other sea-perches, Scorpæna, Serranus, &c., of which these are only a modified and ornate form. The extraordinary expansion of their fins is not, however, accompanied by a similar development of the bones to which they are attached, simply because they appear to have no peculiar function, as in flying fishes, or in those where the spines of the fins are weapons of offence. They attain to the length of twelve inches, and to a weight of about two pounds; they live on small marine animals, and by the Singhalese the flesh (of some at least) is considered good for table. Nine or ten species are known to occur in the East Indian Seas, and of these the one figured above is, perhaps, the most common.
Another species known to occur on the coasts of Ceylon is the Scorpæna miles, Bennett, or Pterois miles, Günther[3351], of which Bennett has given a figure[3352], but it is not altogether correct in some particulars.
In the fishes of Ceylon, however, beauty is not confined to the brilliancy of their tints. In some, as in the /Scarus harid, Forsk[3353], the arrangement of the scales is so graceful, and the effect is so heightened by modifications of colour, as to present the appearance of tessellation, or mosaic work.
Fresh-water Fishes.—Of the fresh-water fish, which inhabit the rivers and tanks, so very little has hitherto been known to naturalists[3354], that of nineteen drawings sent home by Major Skinner in 1852, although specimens of well-known genera, Colonel Hamilton Smith pronounced nearly the whole to be new and undescribed species.
Of eight of these, which were from the Mahawelliganga, and caught in the vicinity of Kandy, five were carps; two were Leucisci, and one a Mastacembelus (M. armatus, Lacep); one was an Ophiocephalus, and one a Polyacanthus, with no serræ on the gills. Six were from the Kalanyganga, close to Colombo, of which two were Helostoma, in shape approaching the Chætodon; two Ophiocephali, one a Silurus, and one an Anabas, but the gills were without denticulation. From the still water of the lake, close to the walls of Colombo, there were two species of Eleotris, one Silurus with barbels, and two Malacopterygians, which appear to be Bagri.
The fresh-water Perches of Europe and of the North of America are represented in Ceylon and India by several genera, which bear to them a great external similarity (Lates, Therapon). They have the same habits as their European allies, and their flesh is considered equally wholesome, but they appear to enter salt-water, or at least brackish water, more freely. It is, however, in their internal organisation that they differ most from the perches of Europe; their skeletons are composed of fewer vertebræ, and the air bladder of the Therapon is divided into two portions, as in the carps. Four species at least of this genus inhabit the lakes and rivers of Ceylon, and one of them, of which a figure is given above, has been but imperfectly described in any ichthyological work[3371]; it attains to the length of seven inches.
In addition to marine eels, in which the Indian coasts abound, Ceylon has some true fresh-water eels, which never enter the sea. These are known to the natives under the name of Theliya, and to naturalists by that of Mastacembelus. They have sometimes in ichthyological systems been referred to the Scombridæ and other marine families, from the circumstance that the dorsal fin anteriorly is composed of spines. But, in addition to the general shape of the body, their affinity to the eel is attested, by their confluent fins, by the absence of ventral fins, by the structure of the mouth and its dentition, by the apparatus of the gills, which opens with an inferior slit, and above all by the formation of the skeleton itself.[3381]
Their skin is covered with minute scales, coated by a slimy exudation, and the upper jaw is produced into a soft tripartite tentacle, with which they are enabled to feel for their prey in the mud. They are very tenacious of life, and belong, without doubt, to those fishes which in Ceylon descend during the drought into the muddy soil.[3382] Their flesh very much resembles that of the eel; and is highly esteemed.[3383] They were first made known to European naturalists by Russell[3384], who brought to Europe from the rivers round Aleppo specimens, some of which are still preserved in the collection of the British Museum. Aleppo is the most western point of their geographical range, the group being mainly confined to the East-Indian continent and its islands.
In Ceylon only one species appears to occur, the Mastacembelus armatus.[3391] The back is armed with from thirty-five to thirty-nine short, stout spines; there being three others before the anal fin. The ground colour of the fish is brown, and the head has two rather irregular longitudinal black bands; deep-brown spots run along the back as well as along the dorsal and anal fins; and the sides are ornamented with irregular and reticulated brown lines. This eel attains to the length of two feet. The old females do not show any markings, being of a uniform brown colour.
In the collection of Major Skinner, before alluded to, brought together without premeditation, the naturalist will be struck by the preponderance of those genera which are adapted by nature to endure, a temporary privation of moisture; and this, taken in connection with the vicissitudes affecting the waters they inhabit, exhibits a surprising illustration of the wisdom of the Creator in adapting the organisation of his creatures to the peculiar circumstances under which they are destined to exist.
So abundant are fish in all parts of the island, that Knox says, not the running streams alone, but the reservoirs and ponds, "nay, every ditch and little plash of water but ankle deep hath fish in it."[3392] But many of these reservoirs and tanks are, twice in each year, liable to be evaporated to dryness till the mud of the bottom is converted into dust, and the clay cleft by the heat into gaping apertures; yet within a very few days after the change of the monsoon, the natives are busily engaged in fishing in those very spots and in the hollows contiguous to them, although the latter are entirely unconnected with any pool or running streams. Here they fish in the same way which Knox described nearly 200 years ago, with a funnel-shaped basket, open at bottom and top, "which," as he says, "they jibb down, and the end sticks in the mud, which often happens upon a fish; which, when they feel beating itself against the sides, they put in their hands and take it out, and reive a ratan through their gills, and so let them drag after them."[3401]
This operation may be seen in the lowlands, traversed by the high road leading from Colombo to Kandy. Before the change of the monsoon, the hollows on either side of the highway are covered with dust or stunted grass; but when flooded by the rains, they are immediately resorted to by the peasants with baskets, constructed precisely as Knox has stated, in which the fish are entrapped and taken out by the hand.[3411]
So singular a phenomenon as the sudden re-appearance of full-grown fishes in places that a few days before had been encrusted with hardened clay, has not failed to attract attention; but the European residents have been content to explain it by hazarding conjectures, either that the spawn must have lain imbedded in the dried earth till released by the rains, or that the fish, so unexpectedly discovered, fall from the clouds during the deluge of the monsoon.
As to the latter conjecture; the fall of fish during showers, even were it not so problematical in theory, is too rare an event to account for the punctual appearance of those found in the rice-fields, at stated periods of the year. Both at Galle and Colombo in the south-west monsoon, fish are popularly believed to have fallen from the clouds during violent showers, but those found on the occasions that give rise to this belief, consist of the smallest fry, such as could be caught up by waterspouts, and vortices analogous to them, or otherwise blown on shore from the surf; whereas those which suddenly appear in the replenished tanks and in the hollows which they overflow, are mature and well-grown fish.[3421] Besides, the latter are found, under the circumstances I have described, in all parts of the interior, whilst the prodigy of a supposed fall of fish from the sky has been noticed, I apprehend, only in the vicinity of the sea, or of some inland water.
The surmise of the buried spawn is one sanctioned by the very highest authority. Mr. Yarrell in his "History of British Fishes," adverting to the fact that ponds (in India) which had been previously converted into hardened mud, are replenished with small fish in a very few days after the commencement of each rainy season, offers this solution of the problem as probably the true one: "The impregnated ova of the fish of one rainy season are left unhatched in the mud through the dry season, and from their low state of organisation as ova, the vitality is preserved till the recurrence, and contact of the rain and oxygen in the next wet season, when vivification takes place from their joint influence."[3431]
This hypothesis, however, appears to have been advanced upon imperfect data; for although some fish, like the salmon, scrape grooves in the sand and place their spawn in inequalities and fissures; yet as a general rule spawn is deposited not beneath but on the surface of the ground or sand over which the water flows, the adhesive nature of each egg supplying the means of attachment. But in the Ceylon tanks not only is the surface of the soil dried to dust after the evaporation of the water, but earth itself, twelve or eighteen inches deep, is converted into sun-burnt clay, in which, although the eggs of mollusca, in their calcareous covering, are in some instances preserved, it would appear to be as impossible for the ova of fish to be kept from decomposition as for the fish themselves to sustain life. Besides, moisture in such situations is only to be found at a depth to which spawn could not be conveyed by the parent fish, by any means with which we are yet acquainted.
But supposing it possible to carry the spawn sufficiently deep, and to deposit it safely in the mud below, which is still damp, whence it could be liberated on the return of the rains, a considerable interval would still be necessary after the replenishing of the ponds with water to admit of vivification and growth. Yet so far from this interval being allowed to elapse, the rains have no sooner fallen than the taking of the fish commences, and those captured by the natives in wicker cages are mature and full grown instead of being "small fish" or fry, as supposed by Mr. Yarrell.
Even admitting the soundness of his theory, and the probability that, under favourable circumstances, the spawn in the tanks might be preserved during the dry season so as to contribute to the perpetuation of their breed, the fact is no longer doubtful, that adult fish in Ceylon, like some of those that inhabit similar waters both in the New and Old World, have been endowed by the Creator with the singular faculty of providing against the periodical droughts either by journeying overland in search of still unexhausted water, or, on its utter disappearance, by burying themselves in the mud to await the return of the rains.
It is an illustration of the eagerness with which, after the expedition of Alexander the Great, particulars connected with the natural history of India were sought for and arranged by the Greeks, that in the works both of ARISTOTLE and THEOPHRASTUS facts are recorded of the fishes in the Indian rivers migrating in search of water, of their burying themselves in the mud on its failure, of their being dug out thence alive during the dry season, and of their spontaneous reappearance on the return of the rains. The earliest notice is in ARISTOTLE'S treatise De Respiratione[3451], where he mentions the strange discovery of living fish found beneath the surface of the soil, "[Greek: tôn ichthyôn oi polloi zôsin en tê gê, akinêtizontes mentoi, kai euriskontai oryttomenoi?]" and in his History of Animals he conjectures that in ponds periodically dried the ova of the fish so buried become vivified at the change of the season.[3452] HERODOTUS had previously hazarded a similar theory to account for the sudden appearance of fry in the Egyptian marshes on the rising of the Nile; but the cases are not parallel. THEOPHRASTUS, the friend and pupil of Aristotle, gave importance to the subject by devoting to it his essay [Greek: Peri tês tôn ichthyôn en zêrô diamonês], De Piscibus in sicco degentibus. In this, after adverting to the fish called exocoetus, from its habit of going on shore to sleep, "[Greek: apo tês koitês,]" he instances the small fish ([Greek: ichthydia]), that leave the rivers of India to wander like frogs on the land; and likewise a species found near Babylon, which, when the Euphrates runs low, leave the dry channels in search of food, "moving themselves along by means of their fins and tail." He proceeds to state that at Heraclea Pontica there are places in which fish are dug out of the earth, "[Greek: oryktoi tôn ichthyôn]," and he accounts for their being found under such circumstances by the subsidence of the rivers, "when the water being evaporated the fish gradually descend beneath the soil in search of moisture; and the surface becoming hard they are preserved in the damp clay below it, in a state of torpor, but are capable of vigorous movements when disturbed." "In, this manner, too," adds Theophrastus, "the buried fish propagate, leaving behind them their spawn, which becomes vivified on the return of the waters to their accustomed bed." This work of Theophrastus became the great authority for all subsequent writers on this question. ATHENÆUS quotes it[3461], and adds the further testimony of POLYBIUS, that in Gallia Narbonensis fish are similarly dug out of the ground.[3462] STRABO repeats the story[3463], and the Greek naturalists one and all received the statement as founded on reliable authority.
Not so the Romans. LIVY mentions it as one of the prodigies which were to be "expiated" on the approach of a rupture with Macedon, that "in Gallico agro qua induceretur aratrum sub glebis pisces emersisse,"[3464] thus taking it out of the category of natural occurrences. POMPONIUS MELA, obliged to notice the matter in his account of Narbon Gaul, accompanies it with the intimation that although asserted by both Greek and Roman authorities, the story was either a delusion or a fraud, JUVENAL has a sneer for the rustic—
"miranti sub aratro
Piscibus inventis."—Sat. xiii. 63.
And SENECA, whilst he quotes Theophrastus, adds ironically, that now we must go to fish with a hatchet instead of a hook; "non cum hamis, sed cum dolabra ire piscatum." PLINY, who devotes the 35th chapter of his 9th book to this subject, uses the narrative of Theophrastus, but with obvious caution, and universally the Latin writers treated the story as a fable.
In later times the subject received more enlightened attention, and Beekman, who in 1736 published his commentary on the collection [Greek: Peri Thaumasiôn akousmatôn], ascribed to Aristotle, has given a list of the authorities about his own times,—GEORGIUS AGRICOLA, GESNER, RONDELET, DALECHAMP, BOMARE, and GRONOVIUS, who not only gave credence to the assertions of Theophrastus, but adduced modern instances in corroboration of his Indian authorities.
As regards the fresh-water fishes of India and Ceylon, the fact is now established that certain of them possess the power of leaving the rivers and returning to them again after long migrations on dry land, and modern observation has fully confirmed their statements. They leave the pools and nullahs in the dry season, and led by an instinct as yet unexplained, shape their course through the grass towards the nearest pool of water. A similar phenomenon is observable in countries similarly circumstanced. The Doras of Guiana[3471] have been seen travelling over land during the dry season in search of their natural element[3472], in such droves that the negroes fill baskets with them during these terrestrial excursions. PALLEGOIX in his account of Siam, enumerates three species of fishes which leave the tanks and channels and traverse the damp grass[3481]; and SIR JOHN BOWRING, in his account of his embassy to the Siamese kings in 1855, states, that in ascending and descending the river Meinam to Bankok, he was amused with the novel sight of fish leaving the river, gliding over the wet banks, and losing themselves amongst the trees of the jungle.[3482]
The class of fishes endowed with this power are chiefly those with labyrinthiform pharyngeal bones, so disposed in plates and cells as to retain a supply of moisture, which, whilst they are crawling on land, gradually exudes so as to keep the gills damp.[3483]
The individual most frequently seen in these excursions in Ceylon is a perch called by the Singhalese Kavaya or Kawhy-ya, and by the Tamils Pannei-eri, or Sennal. It is closely allied to the Anabas scandens of Cuvier, the Perca scandens of Daldorf. It grows to about six inches in length, the head round and covered with scales, and the edges of the gill-covers strongly denticulated. Aided by the apparatus already adverted to in its head, this little creature issues boldly from its native pools and addresses itself to its toilsome march generally at night or in the early morning, whilst the grass is still damp with the dew; but in its distress it is sometimes compelled to move by day, and Mr. E.L. Layard on one occasion encountered a number of them travelling along a hot and dusty road under the midday sun.[3484]
Referring to the Anabas scandens, DR. HAMILTON BUCHANAN says, that of all the fish with which he was acquainted it is the most teliacious of life; and he has known boatmen on the Ganges to keep them for five or six days in an earthen pot without water, and daily to use what they wanted, finding them as lively and fresh as when caught.[3491] Two Danish naturalists residing at Tranquebar, have contributed their authority to the fact of this fish ascending trees on the coast of Coromandel, an exploit from which it acquired its epithet of Perca scandens. DALDORF, who was a lieutenant in the Danish East India Company's service, communicated to Sir Joseph Banks, that in the year 1791 he had taken this fish from a moist cavity in the stem of a Palmyra palm, that grew near a lake. He saw it when already five feet above the ground struggling to ascend still higher;—"suspending itself by its gill-covers, and bending its tail to the left, it fixed its anal fin in the cavity of the bark, and sought by expanding its body to urge its way upwards, and its march was only arrested by the hand with which he seized it."[3501]
There is considerable obscurity about the story of this ascent, although corroborated by M. JOHN. Its motive for climbing is not apparent, since water being close at hand it could not have gone for sake of the moisture contained in the fissures of the palm; nor could it be in search of food, as it lives not on fruit but on aquatic insects.[3502] The descent, too, is a question of difficulty.
The position of its fins, and the spines on its gill-covers, might assist its journey upwards, but the same apparatus would prove anything but a facility in steadying its journey down. The probability is, as suggested by Buchanan, that the ascent which was witnessed by Daldorf was accidental, and ought not to be regarded as the habit of the animal. In Ceylon I heard of no instance of the perch ascending trees[3511], but the fact is well established that both it, the pullata (a species of polyacanthus), and others, are capable of long journeys on the level ground.[3512]
Burying Fishes.—But a still more remarkable power possessed by some of the Ceylon fishes, is that already alluded to, of secreting themselves in the earth in the dry season, at the bottom of the exhausted ponds, and there awaiting the renewal of the water at the change of the monsoon. The instinct of the crocodile to resort to the same expedient has been already referred to[3513], and in like manner the fish, when distressed by the evaporation of the tanks, seek relief by immersing first their heads, and by degrees their whole bodies, in the mud; sinking to a depth at which they find sufficient moisture to preserve life in a state of lethargy long after the bed of the tank has been consolidated by the intense heat of the sun. It is possible, too, that the cracks which reticulate the surface may admit air to some extent to sustain their faint respiration.
The same thing takes place in other tropical regions, subject to vicissitudes of drought and moisture. The Protopterus[3521], which inhabits the Gambia (and which though demonstrated by Professor Owen to possess all the essential organisation of fishes, is nevertheless provided with true lungs), is accustomed in the dry season, when the river retires into its channel, to bury itself to the depth of twelve or sixteen inches in the indurated mud of the banks, and to remain in a state of torpor till the rising of the stream after the rains enables it to resume its active habits. At this period the natives of the Gambia, like those of Ceylon, resort to the river, and secure the fish in considerable numbers as they flounder in the still shallow water. A parallel instance occurs, in Abyssinia in relation to the fish of the Mareb, one of the sources of the Nile, the waters of which are partially absorbed in traversing the plains of Taka. During the summer its bed is dry, and in the slime at the depth of more than six feet is found a species of fish without scales, different from any known to inhabit the Nile.[3522]
In South America the "round-headed hassar" of Guiana, Callicthys littoralis, and the "yarrow," a species of the family Esocidæ, although they possess no specially modified respiratory organs, are accustomed to bury themselves in the mud on the subsidence of water in the pools during the dry season.[3531] The Loricaria of Surinam, another Siluridan, exhibits a similar instinct, and resorts to the same expedient. Sir R. Schomburgk, in his account of the fishes of Guiana, confirms this account of the Callicthys, and says "they can exist in muddy lakes without any water whatever, and great numbers of them are sometimes dug up from such situations."[3532]
In those portions of Ceylon where the country is flat, and small tanks are extremely numerous, the natives are accustomed in the hot season to dig in the mud for fish. Mr. Whiting, the chief civil officer of the eastern province, informs me that, on two occasions, he was present accidentally when the villagers were so engaged, once at the tank of Malliativoe, within a few miles of Kottiar, near the bay of Trincomalie, and again at a tank between Ellendetorre and Arnitivoe, on the bank of the Vergel river. The clay was firm, but moist, and as the men flung out lumps of it with a spade, it fell to pieces, disclosing fish from nine to twelve inches long, which were full grown and healthy, and jumped on the bank when exposed to the sun light.
Being desirous of obtaining a specimen of fish so exhumed, I received from the Moodliar of Matura, A.B. Wickremeratne, a fish taken along with others of the same kind from a tank in which the water had dried up; it was found at a depth of a foot and a half where the mud was still moist, whilst the surface was dry and hard. The fish which the moodliar sent to me is an Anabas, closely resembling the Perca scandens of Daldorf; but on minute examination it proves to be a species unknown in India, and hitherto found only in Boreno and China. It is the A. oligolepis of Bleek.
But the faculty of becoming torpid at such periods is not confined in Ceylon to the crocodile sand fishes;—it is also possessed by some of the fresh-water mollusca and aquatic coleoptera. One of the former, the Ampullaria glauca, is found in still water in all parts of the island, not alone in the tanks, but in rice-fields and the watercourses by which they are irrigated. When, during the dry season, the water is about to evaporate, it burrows and conceals itself[3551] till the returning rains restore it to activity, and reproduce its accustomed food. There, at a considerable depth in the soft mud, it deposits a bundle of eggs with a white calcareous shell, to the number of one hundred or more in each group. The Melania Paludina in the same way retires during the droughts into the muddy soil of the rice lands; and it can only be by such an instinct that this and other mollusca are preserved when the tanks evaporate, to re-appear in full growth and vigour immediately on the return of the rains.[3552]
Dr. John Hunter[3561] has advanced an opinion that hybernation, although a result of cold, is not its immediate consequence, but is attributable to that deprivation of food and other essentials which extreme cold occasions, and against the recurrence of which nature makes a timely provision by a suspension of her functions. Excessive heat in the tropics produces an effect upon animals and vegetables analogous to that of excessive cold in northern regions, and hence it is reasonable to suppose that the torpor induced by the one may be but the counterpart of the hybernation which results from the other. The frost that imprisons the alligator in the Mississippi as effectually cuts it off from food and action as the drought which incarcerates the crocodile in the sun-burnt clay of a Ceylon tank. The hedgehog of Europe enters on a period of absolute torpidity as soon as the inclemency of winter deprives it of its ordinary supply of slugs and insects; and the tenrec[3562] of Madagascar, its tropical representative, exhibits the same tendency during the period when excessive heat produces in that climate a like result.
The descent of the Ampullaria, and other fresh-water molluscs, into the mud of the tanks, has its parallel in the conduct of the Bulimi and Helices on land. The European snail, in the beginning of winter, either buries itself in the earth or withdraws to some crevice or overarching stone to await the returning vegetation of spring. So, in the season of intense heat, the Helix Waltoni of Ceylon, and others of the same family, before retiring under cover, close the aperture of their shells with an impervious epiphragm, which effectually protects their moisture and juices from evaporation during the period of their æstivation. The Bulimi of Chili have been found alive in England in a box packed in cotton after an interval of two years, and the animal inhabiting a land-shell from Suez, which was attached to a tablet and deposited in the British Museum in 1846, was found in 1850 to have formed a fresh epiphragm, and on being immersed in tepid water, it emerged from its shell. It became torpid again on the 15th November, 1851, and was found dead and dried up in March, 1852.[3571] But exceptions serve to prove the accuracy of Hunter's opinion almost as strikingly as accordances, since the same genera of animals that hybernate in Europe, where extreme cold disarranges their oeconomy, evince no symptoms of lethargy in the tropics, provided their food be not diminished by the heat. Ants, which are torpid in Europe during winter, work all the year round in India, where sustenance is uniform.[3572] The shrews of Ceylon (Sorex montanus and S. ferrugineus of Kelaart), like those at home, subsist upon insects, but as they inhabit a region where the equable temperature admits of the pursuit of their prey at all seasons of the year, unlike those of Europe, they never hybernate. A similar observation applies to bats, which are dormant during a northern winter when insects are rare, but never become torpid in any part of the tropics. The bear, in like manner, is nowhere deprived of its activity except when the rigour of severe frost cuts off its access to its accustomed food. On the other hand, the tortoise, which in Venezuela immerses itself in indurated mud during the hot months shows no tendency to torpor in Ceylon, where its food is permanent; and yet it is subject to hybernation when carried to the colder regions of Europe.
To the fish in the detached tanks and pools when the heat, by exhausting the water, deprives them at once of motion and sustenance, the practical effect must be the same as when the frost of a northern winter encases them in ice. Nor is it difficult to believe that they can successfully undergo the one crisis when we know beyond question that they may survive the other.[3581]
Hot-water Fishes.—Another incident is striking in connection with the fresh-water fishes of Ceylon. I have described elsewhere the hot springs of Kannea[3582], in the vicinity of Trincomalie, the water in which flows at a temperature varying at different seasons from 85° to 115°. In the stream formed by these wells M. Reynaud found and forwarded to Cuvier two fishes which he took from the water at a time when his thermometer indicated a temperature of 37° Reaumur, equal to 115° of Fahrenheit. The one was an Apogon, the other an Ambassis, and to each, from the heat of its habitat, he assigned the specific name of "thermalis."[3591]
List of Ceylon Fishes.
In the following list, the Acanthopterygian fishes of Ceylon has been prepared for me by Dr. G&ÜNTHER, and will be found the most complete which has appeared of this order. I am also indebted to him for the correction of the list of Malacopterygians, which I hope ere long to render still more extended, as well as that of the Cartilaginous fishes.