Page:Popular Science Monthly Volume 8.djvu/691

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ANIMAL PARASITES AND MESSMATES.
671

pine Islands which bore considerable resemblance in this respect to a hotel with its table-d'hôte.

A somewhat more excusable piece of pauperism is found in the case of an eel, which ensconces itself in the branchial sac of that curious fish known as the angler, or fishing-frog (Fig. 1), where he afterward plays the part of a messmate. Although the eels generally

Fig. 1.—The Angler-Fish.

get their living easily, the angler possesses fishing-implements which are wanting in them, and, when immersed in the ooze, it carries on a fishery sufficiently abundant for both. This relationship was first observed by Risso in the Mediterranean; the same fish in more northern seas has since been found to harbor, in like manner, an amphipod crustacean.

Another remarkable example of this kind of association among fish was made known by Reinhardt, of Copenhagen. A siluroid fish occurring in Brazil, and possessed of numerous barbules that make it successful as a fisherman, lodges in the cavity of its mouth some very small fishes, that for a long time were supposed to be young siluroids; it was believed that the mother brought her progeny to maturity in the mouth, as marsupials do in the abdominal pouch, or as some other fishes do. But this is a mistake. The supposed young are perfectly developed adult fish, that, instead of living by their own