Democratic Sentinel, Volume 8, Number 43, Rensselaer, Jasper County, 21 November 1884 — LIVING IN A SEA-CUCUMBER. [ARTICLE]

LIVING IN A SEA-CUCUMBER.

The Cartons Fiih Which Exist Inside an Animated Lodging-Hon se. In walking along the half-submerged fringing reef of the Tortugas group of islands my attention was attracted by numbers of great, black, worm-like creatures strewn over the bottom just within the breakers. They were Holothurians. or sea-cucumbers. The seacucumber looks like a great, grotesque caterpillar, made out of leather and filled with water, and handling causes it to eject two streams cf water with considerable force. After placing one of them upon the seat of the boat, we found that the creature had ejected all of its interior organs-actually thrown them off. This would have been a grievous calamity to almost any animal except a sea-cucumber; but they have the faculty of reproducing lost parts to a wonderful degree, and if placed back in the water would soon provide themselves with an entirely new set. If kept for a long time without food, a ring will be formed about the tail which grows deeper and deeper, until finally the piece drops off. In a short time another ring appears and another piece is sacrificed—a most remarkable operation, you will say, *but quite ingenious when we understand it. The animal is merely retrenching, and as the food supply becomes smaller and smaller, portions of the body are thrown off, so that there will not be so much to feed, until at last the sea-cucumber •will sacrifice its entire body to save the mouth or head, and finally this dies. I caught one and put it in a glass jar. Being a large animal, it had soon exhausted the air in the water, and twisted its body deliberately about to show its discomfort, for the sea-cucumber and all ether water animals require air just as luiv ias ourselves. For several f moments the sea-cucumber writhed about in its lazy fashion, when, all at once, out of one end I saw peeping a curions, delicate head. A moment later it was still further out—a transparent, shining fish, and soon, with a convulsive wriggle, it freed itself from its strange prison and swam about a moment, then settled to the bottom. Its body was so delicate and transparent that print could almost be read through it, and a specimen that I have before me now, though shrunk and hardened in alcohol for several years, is still almost like glass. But how did the fish get in the seacucumber ? This was, at first, a puzzle, and to ascertain whether it was accidental or not, we collected a large number of cucumbers ( Holothura fioridiana), and in nearly every case, as soon as the animal had exhausted the air in our aquarium, the silvery, eel-like fierasfer—for this is the fish’s name—would come wriggling out, swim about for a moment as if dazzled and bewildered, and then sink to the bottom and die. It was evident that the fish was not eaten by the liolothurian, and equally plain that the fish was not adapted for the outside world. Hence, we assumed that the tier as ter was a boarder in the cucumber, and such is really the case. Though I made many experiments, the fish could never be induced to return to its home, though freshly aerated water was constantly supplied. The conclusion that seemed most tenable was highly improbable, and so the puzzle remained until it was solved by the curator of the great aquarium at Naples, Italy. He found that his sea cucumbers were also inhabited by a fierasfer, and, by carefully watching them, he saw the fishes come out and return. In the. large tank the fishes ventured out, swam around, and probably fed, and finally returned; and here is probably the most remarkable I)art of it. Instead of returning head first, as you would naturaly expect, the fierasfer slipped, not its head, but the tip of its tail into the orifice. In a moment the sea-cu-cumber relaxed to draw in water, and the cunning fish slipped in an inch then rested; another., relaxation by thq cucumber, and another inch gained, an 4 so on, until, to the -amazement of the Italian naturalist, the fierasfer disappeared, tail first, within the very accommodating animal. The fierasfer then is a boarder in the sea-cucumber, a tenant that not only lives upon its host without pay, but does not hesitate to attack it when hungry. * This has been proved by Prof. Semper, who found pieces of the water-lung of thjß living hotel in the stomach of the boarder ; but, as we have seen, the former is able to reproduce lost parts, and probably does not suffer. The boarder also undoubtedly feeds upon food taken by its host.— Prof. Holden , in Golden Days.