Fig. 353. The Pickled Dog-fish (Acanthias vulgaris).
The Dog-fish, Acanthias vulgaris (Fig. 353), which sometimes attains the length of between three and four feet, is exceedingly voracious. It feeds upon other fish, of which it destroys great quantities; it does not hesitate to attack the fishermen, and especially bathers in the sea. It places itself in ambush, like the Raias, in order to attack its prey. The flesh of the dog-fish is hard, smells of musk, and is rarely eaten; but the skin becomes an article of commerce, and is known as shagrin, being, like the skin of the shark, used for making spectacle-cases and for other ornamental purposes, for which its green colour and high polish recommend it. There is a smaller species than the preceding, which haunts rocky shores, where it lies in wait for its prey. Its spots are larger and more scattered, and its ventral fins are nearly square. It feeds on molluscs, crustaceans, and small fishes.
Fig. 354. The Hammerhead (Zygæna malleus).
The Hammerhead, Zygæna malleus (Fig. 354), is chiefly distinguished by the singular conformation of its head, which is flattened horizontally, truncate in front, and the sides prolonged transversely, giving it the appearance of the head of a hammer. The eyes of this fish are placed at the extremity of the lateral prolongations of the head; they are grey, projecting, and the iris is gold-coloured. When the animal is irritated, the colours of the iris become like flame, to the horror of the fishermen who behold them.
Beneath the head and near to the junction of the trunk is the mouth, which is semicircular, and furnished on each jaw with three or four rows of large teeth, pointed and barbed on two sides.
The most common species in our seas is long and slender in the body, which is grey, the head blackish. It usually attains the length of eleven or twelve feet, weighing occasionally nearly five hundred pounds. Its boldness and voracity, and craving for blood, are more remarkable than its size. If the hammerhead has not the strength of the shark, it surpasses it in fury; few fishes are better known to sailors in consequence of its striking conformation. Its voracity often brings it round ships even in roadsteads, and near the coast. Its visits impress themselves on the memory of the sailor, and he loves to relate his hairbreadth escape from the meeting.
The saw-fish is distinguished from all other known fishes by the formidable arm which it carries in its head. This weapon is a prolongation of the muzzle, which, in place of being rounded off or reduced to a point, forms a long, strong, straight, sword-like termination, flat on both sides, but on the two edges it is furnished with numerous strong teeth of considerable length, which are prolongations of the hard, bony substance which forms the muzzle—forming, in short, a sword-blade deeply toothed on each edge.
Thus armed, the saw, or sword-fish, as it is sometimes called, the length of which is from twelve to fifteen feet, fearlessly attacks the most formidable inhabitants of the sea. With its threatening weapon, sometimes two yards in length, it dares to measure its strength with the whale. All fishermen who visit the northern seas assert that the meeting of these ocean potentates is always followed by a combat of the most singular kind, in which the activity of the sword-fish is a match for the formidable strength of the whale. Occasionally it dashes itself with such force against the sides of a ship, that its sword is broken in the timber. In the British Museum the blade of a sword-fish may be seen which was thus implanted in the timber of a ship.
III. Sturiona.