SHARK - (A) INTRODUCTION. -- The systematic position of the group of Sharks or Selachoidei in the class of Fishes, their classification, and their general external and anatomical characteristics have been already sufficiently noticed under ICHTHYOLOGY (vol. xii. pp. 630 sq.), and we have here to supplement that article only by a fuller reference to the natural history of the more common and more important types of the group.

Sharks are almost exclusively inhabitants of the sea, but some species freely enter the mouths of large rivers, and one species (Carcharias gangeticus) occurs frequently high up in the large rivers of India, and in the Tigris about Baghdad, at a distance of 350 miles from the Persian Gulf in a straight line, and has even been reported from a lake in Viti Levu (Fiji Islands) which is shut off from the sea by a cataract. Sharks are found in all seas; most numerous between the tropics, they become scarcer beyond, a few only reaching the Arctic circle; it is not known how far they advance southwards in the Antarctic region. Altogether some hundred and fifty different species have been described.

With regard to their habits many are littoral species, the majority pelagic, and a few are known to belong to the bathybial fauna, having hitherto obtained down to a depth of 500 fathoms.

(B) LITTORAL SHARKS.-- The littoral forms are of small size, and generally known under the name of "dog-fishes," "hounds," &c. Some pelagic sharks of larger size also live near the shore on certain of food, and are as frequently found in the open sea, which is their birthplace; therefore we shall refer to them when we speak of the pelagic kinds.

The majority of the littoral species live on the bottom, sometimes close inshore, and feed on small marine animals or on any animal substance. The following are deserving of special notice.

Fig. 1 -- Teeth of Tope. u, upper; l, lower. (x 2.)

The Tope (Galeus) is common on the coasts not only of England, Ireland, and of the more southern parts of Europe, but also of South Africa, California, Tasmania, and New Zealand. Its teeth are equal in both jaws, of rather small size, flat, triangular, with the point directed towards the one side, and with a notch and denticulations on the shorter side (fig. 1). It is of uniform slaty-grey colour, and attains to a length of 6 feet. The female brings forth some thirty living young at one birth in May. It cannot be regarded as a very destructive fish, but becomes troublesome at times to fishermen by taking their bait and driving away other fish they desire to catch.


Read the rest of this article:
"Shark" Article - Table of Contents