Photo by W. Saville-Kent, F.Z.S.] [Milford-on-Sea.
SPOTTED SHARK.
Note the peculiar shape of the tail, and the aperture behind the eye, known as the "spiracle."
Photo by S. Dalby Smith] [Mevagissey.
BASKING-SHARK.
Regularly hunted on the west coast of Ireland for the sake of the oil obtainable from its liver. Note the keel by the side of the tail.
A commoner British shark (in the limited space allotted, British species must be allowed prior claims) is the Blue Shark, small examples of which, weighing 30 or 40 lbs., the writer has often killed with the rod at Mevagissey. When thus hooked, this fish has a curious and very trying habit of revolving rapidly in the water, scoring its own granulated skin with the line. The Porbeagle-shark, another Cornish species, is of thicker build than the last, and swims with far less graceful movements. It is a deep brown colour above, and its general outline may be likened to that of a torpedo. The Fox-shark, or Thresher, so often seen on hot summer days leaping out of water among the pilchard-shoals, is easily recognised, even at considerable distances, by the disproportionately long upper lobe of the tail-fin. This is the shark which attacks certain of the Whale Tribe. Many who stay at home find it agreeable to cast doubt on the story; but the writer has, in Australian seas, witnessed the sight of two of these sharks flinging themselves on the back of an apparently exhausted whale in such unmistakable circumstances that the only alternative (which the reader may accept, if preferred) is to suppose that they were all congenial playmates.
Before specifying some general characters of this interesting group of predatory fishes, it may be as well briefly to summarise the British Dog-fishes; for the Hammerhead-shark, very common in southern seas, is so rare a visitor to Britain as to be negligible in an epitome of the group. The dog-fishes, then, which trouble fishermen are the Smooth Hound and Rough Hound, the Nurse, the Picked Dog, and the Silver Dog, or Tope. The Nurse and Rough Hound are spotted leopards of the sea, and the latter has a very curious property. If a fresh-caught "row-hound," as the fishermen pronounce the name, be put in a basket or boat's well with pollack and other fishes, the points of contact will be marked by discoloration of its neighbours. This is probably due to some acrid and bleaching secretion of the row-hound's skin, for which some economic use might possibly be found. The Picked Dog, or Spur-dog, has very sharp spines in front of both back-fins, and has therefore to be handled by the fishermen very cautiously, often punishing their hands badly when entangled at night in the nets. Of Smooth Hounds there are two species or varieties, between which there is some confusion, and in one at any rate there are interesting anatomical peculiarities in the unborn fish (like many other sharks and dog-fishes, the smooth hound bears living young instead of depositing eggs), any account of which would obviously be out of place in so short a description.