Sketches of the Natural History of Ceylon Part 32

[Ill.u.s.tration: THE ANABAS OF THE DRY TANKS.]

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[1] 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 sh.e.l.l, 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.[2]

[Footnote 1: A knowledge of this fact was turned to prompt account by Mr. Edgar S. Layard, when holding a judicial office at Point Pedro in 1849. A native who had been defrauded of his land complained before him of his neighbour, who, during his absence, had removed their common landmark, diverting the original watercourse and obliterating its traces by filling it up to a level with the rest of the field. Mr. Layard directed a trench to be sunk at the contested spot, and discovering numbers of the Ampullaria, the remains of the eggs, and the living animal which had been buried for months, the evidence was so resistless as to confound the wrong-doer, and terminate the suit.]

[Footnote 2: For a similar fact relative to the sh.e.l.ls and water beetles in the pools near Rio Janeiro, see DARWIN'S _Nat. Journal_, ch. v. p.

99. BENSON, in the first vol. of _Gleanings of Science_, published at Calcutta in 1829, describes a species of _Paludina_ found in pools, which are periodically dried up in the hot season but reappear with the rains, p. 363. And in the _Journal of the Asiatic Society of Bengal_ for Sept. 1832, Lieut. HUTTON, in a singularly interesting paper, has followed up the same subject by a narrative of his own observations at Mirzapore, wherein June, 1832, after a few heavy showers of rain, that formed pools on the surface of the ground near a mango grove, he saw the _Paludinae_ issuing from the ground, "pus.h.i.+ng aside the moistened earth and coming forth from their retreats; but on the disappearance of the water not one of them was to be seen above ground. Wis.h.i.+ng to ascertain what had become of them he turned up the earth at the base of several trees, and invariably found the sh.e.l.ls buried from an inch to two inches below the surface." Lieut. Hutton adds that the _Ampullariae_ and _Planorbes_, as well as the _Paludinae_ are found in similar situations during the heats of the dry season. The British _Pisidea_ exibit the same faculty (see a monograph in the _Camb. Phil. Trans._ vol. iv.). The fact is elsewhere alluded to in the present work of the power possessed by the land leech of Ceylon of retaining vitality even after being parched to hardness during the heat of the rainless season. LYELL mentions the instance of some snails in Italy which, when they hybernate, descend to the depth of five feet and more below the surface.

_Princip. of Geology,_ &c, p. 373.]

Dr. John Hunter[1] 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 a.n.a.logous 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_[2] of Madagascar, its tropical representative, exhibits the same tendency during the period when excessive heat produces in that climate a like result.

[Footnote 1: HUNTER'S _Observations on parts of the Animal oeconomy_, p.

88.]

[Footnote 2: _Centetes ecaudatus_, Illiger.]

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 sh.e.l.ls with an impervious epiphragm, which effectually protects their moisture and juices from evaporation during the period of their aestivation. 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-sh.e.l.l 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 sh.e.l.l. It became torpid again on the 15th November, 1851, and was found dead and dried up in March, 1852.[1] 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.[2] The shrews of Ceylon (_Sorex monta.n.u.s_ 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.

[Footnote 1: _Annals of Natural History_, 1860. See Dr. BAIRD'S _Account of Helix desertorum; Excelsior,_ &c., ch. i. p. 345.]

[Footnote 2: Colonel SKYES has described in the _Entomological Trans._ the operations of an ant in India which lays up a store of hay against the rainy season.]

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.[1]

[Footnote 1: YARRELL, vol. i. p. 364, quotes the authority of Dr. J.

Hunter in his _Animal oeconomy_, that fish, "after being frozen still retain so much of life as when thawed to resume their vital actions;"

and in-the same volume (_Introd_. vol. i. p. xvii.) he relates from JESSE'S _Gleanings in Natural History_, the story of a gold fish (_Cyprinus auratus_), which, together with the a marble basin, was frozen into one solid lump of ice, yet, on the water being thawed, the fish became as lively as usual. Dr. RICHARDSON in the third vol of his _Fauna Borealis Americana_, says the grey sucking carp, found in the fur countries of North America, may be frozen and thawed again without being killed in the process.]

_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[1], 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 Amba.s.sis, and to each, from the heat of its habitat, he a.s.signed the specific name of "thermalis."[2]

[Footnote 1: See SIR J. EMERSON TENNET's _Ceylon_, &c., vol. ii. p.

496.]

[Footnote 2: CUV. and VAL., vol. iii. p. 363. In addition to the two fishes above named, a loche _Cobitis thermalis_, and a carp, _Nuria thermoicos_, were found in the hot-springs of Kannea, at a heat 40 Cent., 114 Fahr., and a roach, _Leuciscus thermalis_, when the thermometer indicated 50 Cent, 122 Fahr.--_Ib_. xviii. p. 59, xvi. p.

182, xvii. p. 94. Fish have been taken from a hot spring at Pooree when the thermometer stood at 112 Fahr., and as they belonged to a carnivorous genus, they must have found prey living in the same high temperature.--_Journ. Asiatic Soc. of Beng._ vol. vi. p. 465. Fishes have been observed in a hot spring at Manila which raises the thermometer to 187, and in another in Barbary, the usual temperature of which is 172; and Humboldt and Bonpland, when travelling in South America, saw fishes thrown up alive from a volcano, in water that raised the temperature to 210, being two degrees below the boiling point.

PATTERSON'S _Zoology_, Pt. ii. p. 211; YARRELL'S _History of British Fishes_, vol. i. In. p. xvi.]

_List of Ceylon Fishes._

In the following list, the Acanthopterygian fishes of Ceylon has been prepared for me by Dr. GuNTHER, 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.

I. OSSEOUS.

ACANTHOPTERYGII

BERYCIDae, _Lowe_.

Myripristis murdjan, _Forsk_.

Holocentrum rubrum, _Forsk_.

spiniferum, _Forsk_.

diadema, _Lacep_.

PERCIDae, _Gunther_.

*Lates calcarifer, _Bl._ Serra.n.u.s louti, _Forsk_.

pachycentrum, _C. & V._ guttatus, _Bl._ Sonneratii, _C. & V._ angularis, _C.& V._ marginalis, _Bl._ hexagonatis, _Forsk_.

flavocoeruleus, _Lacep_.

biguttatus, _C. & V._ lemniscatus, _C. & V._ Amboinensis, _Bleek_.

boenak, _C. & V._ Grammistes orientalis, _Bl._ Genyoroge Sebae, _C. & V._ Bengalensis, _C. & V._ marginata, _C. & V._ rivulata, _C. & V._ gibba, _Forsk_.

spilura, _Benn_.

Mesoprion aurolineatus, _C. & V._ rangus, _C. & V._ quinquelineatus, _Rupp_.

Johnii, _Bl._ annularis, _C. & V._ ?Priacanthus Blochii, _Bleek_.

Amba.s.sis n. sp., _Gunth_.

Commersonii, _C. & V._ thermalis, _C. & V._ Apogon Ceylonicus, _C. & V._ thermalis, _C. & V._ annularis, _Rupp_. Var. roseipinnis.

Chilodipterus quinquelineatus, _C. & V._

PRISTIPOMATIDae, _Gunther_.

Dules Bennettii, _Bleek_.

*Therapon servus, _Bloch_.

*trivittatus, _Buch. Ham_.

quadrilineatus, _Bl._ *Helotes polytaenia, _Bleek_.

Pristipoma hasta, _Bloch_.

maculatum, _Bl._ Diagramma punctatum, _Ehrenb_.

orientale, _Bl._ poecilopterum, _C. & V._ Blochii, _C. & V._ lineatum, _Gm_.

Radja, _Bleek_.

Lobotes auctorum, _Gunth_.

Gerres oblongus, _C & V._ Scolopsia j.a.ponicus, _Bl._ bimaculatus, _Rupp_.

monogramma, _k. & v. H._ Synagris furcosus, _C. & V._ Pentapus aurolineatus, _Lacep_.

Smaris balteatus, _C. & V._ Caesio coerulaureus, _Lacep_.

MULLIDae, _Gray_.

Upeneus taeniopterus, _C. & V._ Indicus, _Shaw_.

cyclostoma, _Lacep_.

Upe. trifasciatus, _Lacep_.

cinnabarinus, _C. & V._ Upeneoides vittatus, _Forsk._ tragula.

sulphureus, _C. & V._ Mulloides flavolineatus, _Lacep_.

Ceylonicus, _C. & V._

SPARIDae, _Gunther_.

Lethrinus frenatus, _C. & V._ cinereus, _C. & V._ fasciatus, _C. & V._ ?ramak, _Forsk._ opercularis, _C. & V._ erythrurus, _C. & V._ Pagrus spinifer, _Forsk_.

Crysophrys hasta, _Bl._ ?Pimelepterus Ternatensis, _Bleek_.

SQUAMIPINNES, _Gunthier_.

Chaetodon Layardi, _Blyth_.

oligacanthus, _Bleek_.