"In the Orinoco they attain a weight exceeding three pounds, and are formidable indeed. The natives will not go in bathing except in very shallow water, and I know of two instances where men were attacked and severely bitten before they could escape. The fish somewhat resembles a bass in shape, although the mouth is smaller; the jaws are armed with triangular, razor-edged teeth; and as they travel in immense shoals they are capable of easily devouring a man or large animal if caught in deep water.... Usually they are slow to attack unless their appetite has been whetted by a taste of blood from a wound; then, however, their work is done with lightninglike quickness.... To catch them we used a large hook secured to a long wire leader and baited with any kind of raw meat, and they always put up a good fight."
A related fish in the Rio La Plata is almost equally dreaded because of its much greater size and formidable teeth, but it works singly; and Africa has many similar characinids, whose flesh is good food, though full of bones. In this order, too, is now classified the family of the "electric eels" (Gymnotidæ) which are not, however, eels, but merely long, cylindrical fishes, naked and almost finless. The well-known one of the Amazon region grows to a length of eight feet and the thickness of a man's thigh, and is justly feared. It is found only in marshes and in comparatively shallow parts of rivers, to the annoyance of travelers who have to ford at such points, beasts of burden being frequently knocked down by the electric shocks. About four-fifths of the length of the fish is occupied by the tail, which contains the electric organ. This consists of two huge masses filled with a jellylike substance, below the spine, and separated by a narrow median septum. This apparatus is under the control of the fish, which by it may stun or kill an enemy or an intended prey, even at a considerable distance.
The family of the cyprinids—the carp, goldfish, chubs, shiners, loaches, and other "minnows" of this and other countries—contains about 1,300 species, scattered over the whole world except South America, Madagascar, and Australasia. All are fresh-water fishes, feeding on vegetation and small animals; and they vary in size from two or three inches to a six-foot carp—the original home of which, now the cosmopolitan giant of the family, was Asia.
Next to these are placed another extensive fresh-water family, that of the catfishes (Siluridæ). More than 1,000 species, mostly tropical, have been described; these are grouped in eight subfamilies, among which there is a wide diversity in shape and habits—in fact, few of those of foreign lands look at all like the catfishes with which we are familiar in America. Most of them are sluggish, but some actively inhabit swift streams. They can exist not only in foul water, but will live a long time out of this element, and some even make long migrations overland from river to river. One or more fin rays are sharp and poisonous in many species, as boys know who handle the little bullhead incautiously, and an African species is able to administer a strong electric shock. Its apparatus is not a battery of modified muscular tissue, as in other electric fishes, but consists of a thick coat of greasy material surrounding the whole body just beneath the skin. Another general characteristic is the protection and assiduous care given to their eggs and young, most species making some sort of a nest in which the eggs are deposited and the fry kept safe from attack.
The third suborder of teleosts contains eellike fishes of the tropics; and the fourth contains the true eels and their relatives. Our common eel is also "common" in most of the temperate countries of the world, but there are perhaps 150 other species of the family Anguillidæ, a large proportion of which live altogether in the sea, many of them at great depths, and showing strange shapes. The generation of the eel was, until recent years, one of the great mysteries of zoölogy, as no propagation, or any symptoms of it, ever appear in fresh water. Finally it was discovered that a queer, almost transparent, compressed creature, a fraction of an inch long that abounded in the surface waters of the ocean, and which had been a puzzle to naturalists, who called it Leptocephalus, was the larva of some sort of eel. This and other discoveries made it plain that when the eels (of the age of four or five years) leave the rivers and bays of all countries and coasts in the autumn, and go out to sea, they do so to spawn, leaving their eggs on the floor of the ocean, mostly south of Bermuda, according to J. Schmidt. From them hatch the minute larvæ that, as they grow, rise to the surface, and when about a year old appear as the silvery young, called "elvers," that drift on the northward-running currents to the coasts of Europe and North America, and ascend the streams by millions in spring. It is not probable that any of the adult eels that go down to the sea to spawn ever come back; and if any remain in landlocked waters whence they cannot migrate to the salt water, they do not breed; but it must be remembered that eels are able to travel a considerable distance overland, at night, from one piece of water to another, and so many may finally reach the sea.
The next suborder illustrates the remarkable difference in size and external appearance that often marks fishes grouped together by similarity of structure. It includes the muskellunge and all the other pikes and pickerels, and the tiny shiners and "bait minnows" of our rivers and brooks, and those of the Old World, one of which is the smallest fish known; it includes several families of deep-sea fishes, often of quaint form and with curious appendages; here, too, is the valuable blackfish of Alaska, the amphibious, phosphorescent little fish of Indian bays and estuaries which when salted and dried forms the Oriental delicacy called "Bombay duck"; and here are the blind fishes of the Mammoth and other American caves. The Heteromi and Cateosteomi are almost equally miscellaneous assemblages, the most notable members of the latter being the funny little pipefishes and sea horses that lurk in the eelgrass near shore, and the males of which carry the eggs and young about in a pouch on the belly. In the next suborder, Perceosces, we find more strange denizens of the mid-oceanic depths, especially the family Chiasmodontidæ, besides some surface ones of ancient lineage, such as the gar and snakeheads of tropical waters, the flying fish and the mullets. The Anacanthini is a small group containing the remarkable pelagic and abyssal macrurids, the fierce barracudas, and the most valuable single family of food fishes in the whole list—the cods.
The cod family (Gadidæ) has many species in northern seas and a few south of the equator. It includes, besides the cods, the haddock, hake, whiting, coalfish, capelin, ling, and several other market fish of importance. The cod is a deep-water fish which goes about in great schools whose movements are not well understood, but in winter they approach the northern shores of the continent, seeking shallows on which to spawn, and it is then on the "banks," off New England and Newfoundland, that the most profitable fisheries are followed. The cod is extraordinarily prolific, and in addition to this it is propagated artificially more extensively than any other fish.
Thus we come to the last suborder, Acanthopterygii, or "spiny-finned" fishes, in which are classified the greater number of really modern and more or less familiar swimmers in the "briny deep." Among American members are the sunfishes and black bass, the perches and darters; the great family (Serranidæ) of sea bass, snappers and West Indian groupers; the tilefish, which appears and disappears in a puzzling fashion; the grunting drums and their relatives of the Scienidæ; the porgies, sheepshead, and other Sparidæ; the brilliantly colored angel fish of the coral reefs of Bermuda and southward; the surf fishes, so important in California; the wrasses, parrot fish, and globefishes, or boxfishes, that inflate their horny hides when alarmed, until they bob about on the surface like corks.