Natural History in Anecdote / Illustrating the nature, habits, manners and customs of animals, birds, fishes, reptiles, etc., etc., etc.

by Unknown

"Impatient of waiting, and having obtained very uncertain results from an electrical eel that had been brought to us alive, but much enfeebled, we repaired to the Cano de Bera, to make our experiments in the open air, on the borders of the water itself. We set off on the 19th of March for the village of Rastro de Abaxo, thence we were conducted to a stream, which, in the time of drought, forms a basin of muddy water, surrounded by fine trees. To catch the gymnoti with nets is very difficult, on account of the extreme agility of the fish, which bury themselves in the mud like serpents. We would not employ the barbasco, that is to say, the roots of Piscidea erithryna and Jacquinia armillaris, which, when thrown into the pool, intoxicate or benumb these animals. These means would have enfeebled the gymnoti; the Indians therefore told us, that they would 'fish with horses.' We found it difficult to form an idea of this extraordinary manner of fishing; but we soon saw our guides return from the Savannah, which they had been scouring for wild horses and mules. They brought about thirty with them, which they forced to enter the pool.

"The extraordinary noise caused by the horses' hoofs makes the fish issue from the mud, and excites them to combat. These yellowish and livid eels resemble large aquatic serpents, swim on the surface of the water, and crowd under the bellies of the horses and mules. A contest between animals of so different an organization furnishes a very striking spectacle. The Indians, provided with harpoons and long slender reeds, surround the pool closely; and some climb upon the trees, the branches of which extend horizontally over the surface of the water. By their wild cries, and the length of their reeds, they prevent the horses from running away and reaching the bank of the pool. The eels, stunned by the noise, defend themselves by the repeated discharge of their electric batteries. During a long time they seem to prove victorious. Several horses sink beneath the violence of the invisible strokes which they receive from all sides, in organs the most essential to life; and stunned by the force and frequency of the shocks, disappear under the water. Others, panting, with their mane standing erect, and wild looks, expressing anguish, raise themselves and endeavour to flee from the storms by which they are overtaken. They are driven back by the Indians into the middle of the water; but a small number succeeds in eluding the active vigilance of the fishermen. These regain the shore, stumbling at every step, and stretch themselves on the sand, exhausted with fatigue, and their limbs benumbed by the electric shock of the gymnoti.

"In less than five minutes two horses were drowned. The eel, being five feet long, and pressing itself against the belly of the horses, makes a discharge along the whole extent of its electric organs. It attacks at once the heart, the intestines, and the plexus cæliacus of the abdominal nerves. It is natural, that the effect felt by the horses should be more powerful than that produced upon men by the touch of the same fish at any one of his extremities. The horses are probably not killed, but only stunned. They are drowned from the impossibility of rising from amid the prolonged struggle between the other horses and the eels.

"We had little doubt, that the fishing would terminate by killing successively all the animals engaged; but by degrees the impetuosity of this unequal combat diminished, and the wearied gymnoti dispersed. They require a long rest, and abundant nourishment, to repair what they have lost of galvanic force. The mules and horses appear less frightened; their manes are no longer bristled, and their eyes express less dread. The Indians assured us, that when the horses are made to run two days successively into the same pool, none are killed the second day. The gymnoti approach timidly the edge of the marsh, when they are taken by means of small harpoons fastened to long cords. When the cords are very dry, the Indians feel no shock in raising the fish into the air. In a few minutes we observed five eels, the greater part of which were but slightly wounded. Some were taken by the same means towards the evening.

"The temperature of the water in which the gymnoti habitually live is about 86 degrees of Fahrenheit. Their electric force, it is said, diminishes in colder waters. The gymnotus is the largest of electrical fishes. I measured some that were from four feet to five feet three inches long; and the Indians assert, that they have seen them still larger. We found that a fish of three feet ten inches long weighed twelve pounds. The transverse diameter of the body was three inches five lines. The gymnoti of Cano de Bera are of a fine olive-green colour. The under part of the head is yellow, mingled with red. Two rows of small yellow spots are placed symmetrically along the back, from the head to the end of the tail. Every spot contains an excretory aperture. In consequence the skin of the animal is constantly covered with a mucous matter, which, as Volta has proved, conducts electricity twenty or thirty times better than pure water. It is somewhat remarkable, that no electrical fish yet discovered in the different parts of the world, is covered with scales.

"It would be rashness to expose ourselves to the first shocks of a very large and strongly irritated gymnotus. If by chance you receive a stroke before the fish is wounded, or wearied by a long pursuit, the pain and numbness are so violent, that it is impossible to describe the nature of the feeling they excite. I do not remember having ever received from the discharge of a large Leyden jar, a more dreadful shock than that which I experienced by imprudently placing both my feet on a gymnotus just taken out of the water."

The Torpedo. It would be difficult to name two fish more dissimilar in outward appearance than the Gymnotus and the Torpedo, and yet they enjoy in common the unique power of communicating electric shocks. The Gymnotus is a long eel-like fish, the Torpedo is round and flat. The Torpedo belongs to the family of the Rays and sometimes reaches a large size. It is common in the Mediterranean and is sometimes found on the southern coasts of the British Isles.

"Although it has once or twice been caught on our coasts," says Mr. Wood, "it is usually found in the Mediterranean, where its powers are well known, and held in some awe. The shock that the Torpedo gives, of course, varies according to the size of the fish and its state of health, but a tolerably large fish in good health can, for the time, disable a strong man. From the effects of its shock, it is in some parts called the Cramp-fish. It has been known to weigh from seventy to a hundred pounds.

The Shark. The Shark, whose name instinctively suggests a shudder, is the largest of the fishes and one of the largest of marine animals. There are many varieties, and they are found in all seas; some measuring no more than a few feet, others attaining to very large proportions. The Blue Shark of the Mediterranean which measures about eleven feet sometimes approaches the south coast of England and Ireland, as does the Hammer-headed Shark of the Atlantic and the Indian Ocean a shark of twelve feet in length. The Tope, a smaller variety, is often seen in the English channel, as are also several others of the smaller Sharks. The Great Basking Shark which often measures thirty feet in the length is the largest of those which visit the English coast, but like the largest of all the sharks (Rhinodon Typicus), which sometimes exceeds fifty feet in length, is herbivorous, and therefore not bloodthirsty.