CHAPTER XV
THE FEARFUL DEVILFISH AND OTHER RAYS
The rays (order Raiæ) differ from the sharks superficially rather than in structure, where the most important difference is the position of the gill clefts, which are lateral in the sharks and ventral in the rays and skates, as the smaller members of the order are called. The majority of them have a flattened, depressed body, from which the broad, expanded pectoral fins are scarcely distinct, while the tail is usually long and slender, in one family so much so that they are known as "whip rays;" and in some a horny point at the tip is connected with a venom gland so that its pricking is poisonous, and these are called "sting rays." All the rays are carnivorous, but only the sharklike forms (sawfishes and the Rhinobatidæ) actively pursue their prey. The true rays live on the bottom and feed on shellfish and small fishes. Most of them bring forth a few young alive, but many lay eggs in squarish, oblong, leathery cases with tendrils at the corners by which they become moored to eelgrass, etc; they are frequently cast up on beaches, and go by the name of "sea purses," In the earlier stages the young ray is much like a shark, and the enormous development of the pectoral fins does not occur until nearly the time of hatching.
The sawfishes, of which several tropical species are known, besides one common in the Atlantic and Mediterranean, are among the most remarkable of oceanic fishes. The body is slender, sharklike, and of great power. The head is flattened, and the snout projects into a hard, flat, sword-shaped beak, the edges of which are thickly studded with sharp teeth; and this singular weapon places all the large inhabitants of the ocean at the mercy of this powerful marauder--it is the worst enemy of whales, even, in the warmer seas, as is the "killer" in the Arctic region. With it the sawfish cuts and slashes, tearing off pieces of flesh, or ripping open the abdomen of its opponent, then seizing the detached pieces. One can easily picture to himself the slaughter when a sawfish dashes into a school of fishes, squids, or porpoises, and slashes right and left with his ripsaw of a beak. Some of the Oriental species reach, and even exceed, twenty feet in length, and Dr. Day, the Indian ichthyologist, says that such monsters have been known to cut bathers completely in two. The saw of a twenty-foot fish would measure six feet in length and a foot across the base.
The most famous of the rays, probably, are the torpedos, a family with a rounded, instead of the customary triangular outline, and a rather short tail, species of which occur on all tropical and temperate coasts, and are noted for their power to give electric shocks to any living thing touching them.
The electric organs are a pair of large masses lying between the head and the pectoral fins. These are derived mainly from four nerves, which originate from an electric lobe of the medulla oblongata. By means of the electric shocks which they are able to administer at will, the torpedo rays are able to ward off the attacks of enemies, and to kill or paralyze their prey. The action is that of a galvanic battery. The dorsal surface is positive, the ventral negative, and the discharge of a large torpedo is sufficient to temporarily disable a man; yet it is not so powerful as that from a big electric eel.
The huge "sea devils" of which thrilling stories are related are the eagle rays of the family Myliobatidæ, some of which are fifteen or twenty feet across the "wings"; and they are among the most frightful of the dangers to which pearl divers are exposed in their perilous occupation. They are savage beasts, and will even attack a small boat with men in it. The worst of these belong to the vicinity of Panama.