The sword-fish may attain a length of from twelve to sixteen feet, and is then a most formidable monster, to be feared by almost every inhabitant of the ocean, from the whale downwards. But a still more terrible, because a more cruel monster, is the saw-fish, a creature that grows to an even larger size, and carries, as his name implies, a saw, instead of a sword, in front of him. This terrific implement may be as much as two yards in length—just double the length of the other. It is flat and broad, narrowing slowly towards the point; and all the way down, upon each side, it is set with sharp quadrangular teeth, each one being firmly fixed in a socket. The creature’s real teeth are small and weak, so that it is difficult for him to eat hard, firm flesh. He prefers intestines, which are softer, and by means of his saw he is able to procure them. This he does by sinking beneath some unfortunate porpoise or dolphin—perhaps even a shark or a whale—and striking violent lateral blows at its belly; not spearing it with the keen, clean thrust of the sword-fish, but ripping it from side to side. In this way it tears out the entrails of its victim, and then greedily devours them as they float in the water. A more horrible thing can hardly be imagined. There is only this to be said, that the creatures thus cruelly used are as cruel themselves in pursuing and devouring their own prey—or, at least, they are as cruel as they can be. Whether that is a very consolatory reflection I really don’t know, but I can think of no better one. In the sea, even more than upon land, every creature lives by killing and eating other creatures. There are no gentle scenes, or, at least, not many; it is all a carnage. The most peaceable and innocent creatures—the ones that we can think about with most pleasure—are the great toothless whales, for these, though so gigantic, have a gullet too small for a fish of any size to pass down it, and live, for the most part, on infusoria, which are creatures so minute, and so low in the scale of life, that they may almost be looked upon as belonging to the vegetable kingdom.
The whales, indeed, with their great jaws, in which, in a leisurely way, they enclose hosts of creatures so widely distributed, yet at the same time so minute, that they make, as it were, a part of the water, in which they are often only distinguishable by the colour their numbers impart to it, may be said to browse the sea, as oxen and horses browse the fields. Yet these poor, peaceful giants are persecuted, as we have seen, by packs of ravenous creatures against whom their very size makes them almost defenceless. As for the toothed whales, some of them—as, for instance, the killer or grampus—are amongst the most voracious of the dwellers of the sea, so that, from the great cachalot down to the smallest fish, mollusc, or crustacean, it may be said that all marine nature is at fierce, carnivorous war. This war, too, is, for the most part, cannibalistic in its nature, and this cannibalism is of a peculiarly horrid description, since most fish devour numbers of their own offspring, for which, by the laws of nature, they feel no affection, and which they do not even know.
In these latter practices, indeed, the cetaceans, being mammals and very tender parents, do not participate; but there is another honourable exception, and that where we might least of all expect to find it. The sharks, so justly dreaded for their voracity, to which, as is well known, man himself not infrequently falls a victim, are solicitous of their young, with whom, to the number of a dozen or more, the mother swims about and does her best to provide them with food. The pretty little flock gambol and frolic about her, and should anything alarm them, they dart at once into her great mouth, held open to receive them, and disappear down her throat. There they remain till their mother thinks the danger is over, when she opens her mouth again, and they re-emerge. This privilege—and it must sometimes be a valuable one—is also open to the pretty little pilot-fishes which, to the number sometimes of half a dozen, accompany the shark in all its wanderings, and which everybody has read about.
It is generally said in natural history books, that the relations existing between the shark and the pilot-fish are not quite understood: but since it must be an inestimable privilege to a little weakly fishlet that any large fish might snap up, to have a shark for a protector, and a shark-cavern to go into—not in the way that other creatures go into it—and since there is nothing which the shark eats that his friend may not have a share of, if he wants to, I really do not see what more one need understand, as far, at least, as the pilot-fish is concerned. Then, too, if—as there seems little doubt is the case—the pilot-fish acts as a scout for the shark, and brings him to anything eatable that he may find floating about in the sea, this fully explains the part which the shark plays in this little amicable arrangement. He protects his little guide and purveyor, not only by his presence but also by offering him an asylum, and the habit of seeking such an asylum has, no doubt, been acquired by the pilot-fish through his seeing the young sharks do so. He has lived in the nursery with them, and they have taught him the trick. Of course, as the pilot-fish shares in anything the shark gets, his wish to guide the latter to whatever he may be the first to find, as well as the trouble he takes to find it, is easily explained. It is not an unselfish act, but one in his own interests, and thus all the requisites of an association of this sort, between two different species of animals, are fulfilled.[13]
When a shark is caught at sea, the poor little pilot-fish, as he is hauled up on deck, will leap up after him out of the water, in a vain endeavour to follow his life’s companion. It is no use; he falls back again, the blue and golden bands with which his bright little body is decorated glittering in the sun—for there generally is a sun in the regions where these things take place. This certainly looks as though the pilot-fish were genuinely attached to the shark. It seems like the act of a faithful little friend, but it need imply no more than does his habitual following and keeping company with the shark in the sea. To be with the great fish has become an instinct with the little one, and so when the latter sees his convoy going somewhere where he has never gone before, he endeavours to go with him. Still, that a really friendly feeling may, through long association, have arisen between the two companions, though differing so from one another in size and appearance, does not seem impossible, or even unlikely. Of course, in considering a question of this sort, we should first get clear ideas of what friendship really is—the essential elements of which it consists. To do this is not, perhaps, so easy a matter as it may seem. At any rate, it is too difficult to be attempted in a work like this.
I make all these statements in regard to the relations existing between the shark and the pilot-fish, and between the mother shark and her young, upon the authority of Mr. Bullen, author of two interesting works, The Cruise of the Cachalot and Idylls of the Sea. In regard to the reception by the shark into her stomach—or, at least, down her throat—of both her young and the pilot-fish, this certainly does seem surprising, but as Mr. Bullen was, on various occasions, present when a shark was cut open and her family and retainers found inside her, the fact seems established. He writes, too—so I gather—as an eye-witness of the habit au naturel. I do not know, therefore, why there should be no reference to it in works that are supposed to instruct, except that, as a rule, the scientific naturalist has but two lines of conduct in regard to the more picturesque doings of any animal. First, he denies what is not in accordance with his ideas and non-experience, and then he refuses to say anything about such things—cuts them, as it were, even after they have been properly introduced to him, and their respectability vouched for. If he had a third line he might, in time, frankly describe them, but generally he has only those two.
CHAPTER XXII
THE SHARK’S ATTACHÉ—QUEER WAYS OF FISHING—HINTS FOR NAVAL WARFARE—FISH THAT DO FLY.
The little pilot-fish is not the only friend that the shark has. The remora, or sucking-fish, as we shall soon see, is still more attached to him. This is one of the queerest fish in the whole ocean. Others may have a more extraordinary, or, at any rate, a more terrifying appearance, but not one of them is constructed on such an original principle, or has such a very quaint and ingenious process of getting through the world. What the process is may be guessed from the name of sucking-fish, but the remora does not suck with its mouth, but with its head. The whole upper surface of this consists of “a large, flat, plate-like adhesive disc,” and whatever this disc touches it adheres to with the greatest tenacity. The reason is that the air between the plate and anything it lies against is forced out, so that a vacuum is created, and when once this is the case, two things that touch each other always stick together. It is by virtue of this principle that a fly is able to walk along the ceiling, for all its six feet end in so many little adhesive discs or suckers, which act as strongly, in proportion to their size, as does that of the remora. But the remora, when it uses its sucker, does not walk, or even swim, which is the equivalent of walking in a fish; all that is done for it by the shark or turtle, to which it attaches itself. It just swims underneath it, and presses itself against its under side, and there it is carried along as safely as if it were riding in its own carriage—indeed, much more so, for there is less likely to be an accident, and if ever there is, the remora can drop off without being hurt, as people generally are when they jump out of a carriage.