Fear is shown by fish in many ways. There is not an angler unacquainted with the natural timidity of fishes, nor a keeper in charge of a salmon-pass, who does not know how easy it is for poachers to deter the salmon from venturing along the path raised expressly for his use.
Among the coral reefs of the Andaman Islands I found the little Chromis lepisurus abundant. As soon as the water was splashed they appeared to retire for safety to the branching coral, where no large fish could follow them; so frightened did they become that on an Andamanese diving from the side of the boat, they at once sought shelter in the coral, in which they remained until it was removed from the sea. In Burma I observed, in 1869, that when weirs are not allowed to stretch across the rivers (which would impede navigation), the open side as far as the bank is studded with reeds; these, as the water passes over them, cause vibration, and occasion a curious sound alarming the fishes, which, crossing to the weired side of the river, become captured.
Hooker, alluding to gulls, terns, wild geese, and pelicans in the Ganges Valley, observes: "These birds congregate by the sides of pools and beat the water with violence, so as to scare the fish, which then become an easy prey—a fact which was, I believe, first indicated by Pallas during his residence on the banks of the Caspian Sea."[15] Fishes, under the influence of terror, dash about with their fins expanded, and often run into places which must destroy them. Thus droves and droves of sardines in the east, impelled by the terror of pursuing sharks, bonitos, and other voracious fishes, frequently throw themselves on the shores in enormous quantities. Friar Odoric, who visited Ceylon about 1320, says: "There are fishes in those seas which come swimming towards the said country in such abundance, that for a great distance into the sea nothing can be seen but the backs of fishes, which, casting themselves on the shore, do suffer men for the space of three days to come, and to take as many of them as they please, and then they return again into the sea."[16]
Pennant tells us that the river bullhead (Cottus gobio) "deposits its spawn in a hole it forms in the gravel, and quits it with great reluctance." General Hardwicke tells how the gouramy (Osphromenus gouramy), in the Mauritius, forms a nest amongst the herbage growing in the shallow water in the sides of tanks. Here the parent continues to watch the place with the greatest vigilance, driving away any interloping fish. The amphibious walking-fish of Mysore (Ophiocephalus striatus) appears to make a nest very similar to that of the gouramy, and over it the male keeps guard; but should he be killed or captured, the vacant post is filled by his partner. (Colonel Puckle.) When very young the fishes keep with and are defended by their parents, but so soon as they are sufficiently strong to capture prey for themselves they are driven away to seek their own subsistence. (See Fishes of India, p. 362.) But it is not only these monogamous amphibious fishes which show an affection for their eggs and also for their fry, but even the little Etroplus maculatus has been observed to be equally fond of its ova. "The eggs are not very numerous and are deposited in the mud at the bottom of the stream, and, when hatched, both parents guard the young for many days, vigorously attacking any large fish that passes near them."[17]
Although the proceedings of the members of the marine and estuary genus of sea-cat (Tachysurus) and its allies show not quite so distinctly signs of affection, still it must be a well-developed instinct which induces the male to carry about the eggs in its mouth until hatched, and to remove them in this manner when danger is imminent. I have taken the ova just ready for the young to come forth out of the mouth and fauces of the parent (male) fish; and in every animal dissected there was no trace of food in the intestinal tract.
Calling the Fishes.—At many temples in India fishes are called to receive food by means of ringing bells or musical sounds. Carew, in Cornwall, is said to have called the gray mullet together by making a noise like chopping with a cleaver. Lacépède relates that some fishes, which had been kept in the basins out of the Tuileries for more than a century, would come when called by their names, and that in many parts of Germany trout, carp, and tench are summoned to their food by the sound of a bell. These instances are mostly due to the fishes having learned by experience that on the hearing certain sounds they may expect food. But Lacépède mentions that some were able to distinguish their individual names; and the same occurs in India. Lieutenant Connolly[18] remarked upon seeing numerous fishes coming to the ghaut at Sidhnath to be fed when called; and on "expressing our admiration of the size of the fish, 'Wait,' said a bystander, 'until you have seen Raghu.' The Brahmin called out his name in a peculiar tone of voice; but he would not hear. I threw in handful after handful of ottah (flour) with the same success, and was just leaving the ghaut, despairing and doubting, when a loud plunge startled me. I thought somebody had jumped off the bastion of the ghaut into the river, but was soon undeceived by the general shout of 'Raghu, raghu,' and by the fishes, large and small, darting away in every direction. Raghu made two or three plunges, but was so quick in his motions that I was unable to guess at his species." [It may be said in relation to these stories quoted by Dr. Day, that they probably belong to the mythology of fishes. It is very doubtful if fishes are able to make any such discrimination among sounds in the air.]
Sounds of Fishes.—Pallegoix states that in Siam the dog's-tongue (Cynoglossus) is a kind of sole; it attaches itself to the bottom of boats, and makes a sonorous noise, which is more musical when several are stuck to the same boat and act in concert (vol. i. p. 193). These noises can scarcely be due to anger or fear. Sir J. Bowring (vol. ii. p. 276) also remarks upon having heard this fish, "which sticks to the bottoms of the boats, and produces a sound something like that of a jew's-harp struck slowly, though sometimes it increases in loudness, so as to resemble the full tones and sound of an organ. My men have pointed me out a fish about four inches long as the author of the music."
Some years since, at Madras, I (Dr. Day) obtained several specimens of a fresh-water Siluroid fish (Macrones vittatus) which is termed the "fiddler" in Mysore. I touched one which was on the wet ground, at which it appeared to become very irate, erecting its dorsal fin, making a noise resembling the buzzing of a bee. Having put some small carp into an aquarium containing one of these fishes, it rushed at a small example, seized it by the middle of its back, and shook it like a dog killing a rat; at this time its barbels were stiffened out laterally like a cat's whiskers.
Many fish when captured make noises, perhaps due to terror. Thus the Carangus hippos, Tetraodon, and others grunt like a hog. Darwin (Nat. Journ., vol. vii) remarks on a catfish found in the Rio Paraná, and called the armado, which is remarkable for a harsh grating noise when caught by hook and line; this noise can be distinctly heard when the fish is beneath the water.
The cuckoo-gurnard (Trigla pini) and the maigre (Pseudosciæna aquila) utter sounds when taken out of the water; and herrings, when the net has been drawn over them, have been observed to do the same: "this effect has been attributed to an escape of air from the air-bladder; but no air-bladder exists in the Cottus, which makes a similar noise."