Photo R. Lazarnick] [New York.
CAT-FISHES.
These belong to the unarmoured group.
The Electric Eel is an extremely abundant fish in the rivers and lagoons of Brazil and the Guianas. It is the most powerful of the electric fishes, and attains a length of 6 feet. The electric organs of this fish are sufficiently strong to kill by their shock other fishes and even mammals. The traveller Humboldt is responsible for the statement, now generally discredited, that the Indians procured this fish by driving horses into the water, and so provoking such violent discharges from the fish that they became exhausted and fell an easy prey.
The Cat-fishes, or Sheath-fishes, are an extremely interesting group, one of the principal characteristics of which is the total absence of scales, the body being either entirely naked or armed with bony tubercles or overlapping plates. Another peculiarity of these fishes is the presence of feelers round the mouth; these, by their delicate sense of touch, enable the fish to procure its food in extremely muddy water, when the eyes would be useless. The latter, indeed, in many species are extremely reduced in size. Many cat-fishes are armed with powerful spines, attached to the body by a very complicated mechanism. Such spines are capable of inflicting dangerous wounds, either by the introduction of poison or the violent inflammation following on the laceration of the wounded part. Some species have elaborate accessory breathing-organs, enabling them to travel overland for short distances from one piece of water to another. Other members of the group possess electrical organs of considerable power; one species inhabiting the Nile attains a length of 4 feet.
The nesting-habits of the group are exceedingly interesting, some building nests in which to deposit the eggs; others carry the eggs in the mouth till they hatch. In one species the care of the eggs is undertaken by the female, which carries them about embedded in the skin of the under surface of the body, which at this season becomes very soft and spongy. When the eggs are laid, she presses them into the spongy skin by lying on them.
The cat-fishes are of world-wide distribution, but only one species, the Wels, occurs in European waters. It commonly attains a length of from 6 to 9 feet, and occasionally as much as 13 feet. The majority of cat-fishes inhabit fresh-water, but some are marine.