The limbs even of the strongest man are benumbed, and he is struck down helpless, by a discharge from the battery of the gymnotus. The organs which produce this curious electrical effect are placed along the under side of the tail. They may be compared to a series of columns inclosed in a thin membrane packed closely together, which, consisting of a series of fiat discs, may be imitated by placing a number of coins with their discs parallel to each other, and with a bladder between each, separated by a gelatinous substance. These columns are technically called septa; and La Cepède calculates that two hundred and forty transverse membranes are packed in each inch, thereby giving to an electric eel eight feet in length an organ cavity of two hundred and forty-six square feet—an enormous extent, as may be supposed, of electricity producing surface. The whole apparatus is supplied with nerves which run through the entire length of the body.
Sting-Rays.
A fresh-water species of sting-ray is an inhabitant of the creeks and lagoons of stagnant water; and so infested are some of them with the creatures, that it is almost certain destruction to venture into them. The sting-ray is circular and flat, with a tail above a foot in length, very thick at the base, and tapering towards the end. Near the middle, on the upper part, it is armed with a long and sharp-pointed sting, finely serrated on two sides, which the fish can raise or depress at will. When disturbed, by a quick movement of the tail out darts its sting towards the object, which it seldom fails to reach. The wound thus inflicted is so severe that the whole nervous system is convulsed, the person becoming rigid and benumbed in a few moments. Long after the most violent effects of the wound have subsided, the part affected retains a sluggish ulceration, which has often baffled the skill of the best surgeons.
They frequent the shallow banks of muddy pools, where they may be constantly seen watching for their prey, and, as if conscious of their powers, scarcely deign to move off when approached. They have their enemies in vultures and other birds of prey; and as they are considered fit for food, war with spear and talon is constantly waged upon them.
Serrosalmus Piraya.
In the Orinoco another dangerous creature exists, called by the natives piraya, with a head shaped somewhat like a sabre. The lower jaw is furnished with a formidable pair of fangs, not unlike those of the rattlesnake. With these it inflicts a gash as smooth as if cut with a razor.
The Caribe.
Every feature of the savage caribe denotes the ferocity and sanguinary nature of its tastes. The piercing eye, surrounded by a bloody-looking ring, is expressive of its cruel and bloodthirsty disposition. Its under jaw, lined with a thick cartilaginous membrane, adds greatly to its strength, protruding considerably beyond the upper, and increasing the ferocious expression of its countenance. Large spots of a brilliant orange hue cover a great portion of its body. Towards the back it is of a bluish ash colour, with a slight tint of olive-green; the intermediate spaces being of pearly white, while the gill-coverts are tinged with red.
So sharp are its triangular teeth, arranged like those of the shark, that neither twine, copper, nor steel can withstand them. At the sight of any red substance, blood especially, they swim forward to the attack; and as they usually move in swarms, it is extremely dangerous for man or beast to enter the water with even a scratch upon their bodies. Horses wounded by the spur are particularly exposed to their attacks when fording a stream; and so rapid is the work of destruction, that unless immediate assistance is rendered, the fish soon penetrate the abdomen of the animal and destroy it: hence the name given to them by the Spaniards means “tripe-eater.” When a net is drawn on shore, numbers of these little pests are seen jumping in the crowd, their jaws wide open, tearing whatever comes in their way, and especially the meshes of the nets, which they soon render useless.
Some tribes of natives place their dead in the water, when these creatures speedily eat the flesh off the bones, which are then preserved in baskets.