Fish As Fathers
by
Comparatively little is known as yet, even in this age of publicity, about the domestic arrangements and private life of fishes. Not that the creatures themselves shun the wiles of the interviewer, or are at all shy and retiring, as a matter of delicacy, about their family affairs; on the contrary, they display a striking lack of reticence in their native element, and are so far from pushing parental affection to a quixotic extreme that many of them, like the common rabbit immortalised by Mr. Squeers, ‘frequently devour their own offspring.’ But nature herself opposes certain obvious obstacles to the pursuit of knowledge in the great deep, which render it difficult for the ardent naturalist, however much he may be so disposed, to carry on his observations with the same facility as in the case of birds and quadrupeds. You can’t drop in upon most fish, casually, in their own homes; and when you confine them in aquariums, where your opportunities of watching them through a sheet of plate-glass are considerably greater, most of the captives get huffy under the narrow restrictions of their prison life, and obstinately refuse to rear a brood of hereditary helots for the mere gratification of your scientific curiosity.
Still, by hook and by crook (especially the former), by observation here and experiment there, naturalists in the end have managed to piece together a considerable mass of curious and interesting information of an out-of-the-way sort about the domestic habits and manners of sundry piscine races. And, indeed, the morals of fish are far more varied and divergent than the uniform nature of the world they inhabit might lead an a priori philosopher to imagine. To the eye of the mere casual observer every fish would seem at first sight to be a mere fish, and to differ but little in sentiments and ethical culture from all the rest of his remote cousins. But when one comes to look closer at their character and antecedents, it becomes evident at once that there is a deal of unsuspected originality and caprice about sharks and flat-fish. Instead of conforming throughout to a single plan, as the young, the gay, the giddy, and the thoughtless are too prone to conclude, fish are in reality as various and variable in their mode of life as any other great group in the animal kingdom. Monogamy and polygamy, socialism and individualism, the patriarchal and matriarchal types of government, the oviparous and viviparous methods of reproduction, perhaps even the dissidence of dissent and esoteric Buddhism, all alike are well represented in one family or another of this extremely eclectic and philosophically unprejudiced class of animals.
If you want a perfect model of domestic virtue, for example, where can you find it in higher perfection than in that exemplary and devoted father, the common great pipe-fish of the North Atlantic and the British Seas? This high-principled lophobranch is so careful of its callow and helpless young that it carries about the unhatched eggs with him under his own tail, in what scientific ichthyologists pleasantly describe as a subcaudal pouch or cutaneous receptacle. There they hatch out in perfect security, free from the dangers that beset the spawn and fry of so many other less tender-hearted kinds; and as soon as the little pipe-fish are big enough to look after themselves the sac divides spontaneously down the middle, and allows them to escape, to shift for themselves in the broad Atlantic. Even so, however, the juniors take care always to keep tolerably near that friendly shelter, and creep back into it again on any threat of danger, exactly as baby-kangaroos do into their mother’s marsupium. The father-fish, in fact, has gone to the trouble and expense of developing out of his own tissues a membranous bag, on purpose to hold the eggs and young during the first stages of their embryonic evolution. This bag is formed by two folds of the skin, one of which grows out from each side of the body, the free margins being firmly glued together in the middle by a natural exudation, while the eggs are undergoing incubation, but opening once more in the middle to let the little fish out as soon as the process of hatching is fairly finished.