Cookiecutter shark

Zigarrenhai ( Isistius brasiliensis)

The Zigarrenhai ( Isistius brasiliensis) is a small member of sharks, the ( Isistius ) belongs to the kind of cigar sharks of the family of dogfish ( Squalidae ).

Physique

The Zigarrenhai is a maximum of 50 inches long and is of uniformly brownish color. Near the gills, the animals have a black band that goes around the body. The Zigarrenhai has a short, rounded snout with wide front seat, eyes wide. Its name stems from its body shape to. Like its closest relative, the big tooth - Zigarrenhai ( Isistius plutodus ), also owns the Zigarrenhai a conspicuous "asymmetrical " Teeth: The teeth of the upper jaw are small and needle-like, while the teeth are grown together to form a row of teeth in the lower jaw. The two dorsal fins ( fins), of which the first is less than the second, set very far back in the back where there is no anal fin and the caudal fin is " asymmetric" formed in the side aspect. The fins ends are almost transparent. Although both types are counted among the spiny dogfish, they have no spines before the dorsal fin. On the underside of the abdomen they lead light organs; Zigarrenhai the remains of which only the exception of the dark collar game.

Dissemination

Since the Zigarrenhai inhabited the deeper regions of the seas from 80 to 3,500 meters deep, only on the basis of ad hoc observations in the Bahamas, off the southern coast of Brazil to the Cape Verde Islands, off the south coast of Africa (Angola and South Africa), as well as Mauritius to New Guinea, to infer a worldwide distribution in tropical seas off the west coast of Australia, from Japan to Hawaii and the Galapagos Islands. The very oily liver helps the animals to move vertically in the water column.

Reproduction

Studies on a captive, pregnant females show that a number of embryos that are equipped with a yolk sac, grow in the womb and probably born after the exhaustion of this food stocks are (called Ovoviviparie or " aplazentaler viviparous "). At birth, the animals are probably between fourteen and fifteen inches long. Unborn cigar sharks do not yet have the characteristic bite, the collar color is not available yet.

Diet

The Zigarrenhai probably feeds on invertebrates and of the flesh, which he bites out with the help of his teeth from large fish and marine mammals. At sea creatures such as tunas, giant sharks, elephant seals or whales, the characteristic cone-shaped scar could be detected. This type of diet also founded the English name: cookie cutter shark, which means as much as cookies Stecher - Hai.

Bioluminescence helps the cigar sharks probably in this type of food intake. Viewed from the depth from the lit side of the abdomen can almost compensate for the brightness of the water surface. The dark spot in the collar region may also mimic the silhouette of a small fish. So cigar sharks can attract larger animals, which in turn become prey.