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.
[Illustration: CATERPILLAR PROTECTED BY FORM AND COLOR RESEMBLING THE
TWIGS OF A TREE]
[Illustration: SEA HORSE PROTECTED BY FORM AND COLOR RESEMBLING THE
MARINE PLANTS AMONG WHICH IT LIVES]
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.
[Illustration: THE GILA MONSTER, FEARED THOUGH ITS BITE IS NOT ALWAYS
DEADLY TO MAN
Photo, Elwin R. Sanborn, N. Y. Zoological Society]
[Illustration: THE IGUANA, A REMARKABLE LIZARD OF THE NEW WORLD
Photo, Ewing Galloway]
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.