Catshark.

The cat sharks or catsharks are a family (Scyliorhinidae) of sharks, with over 110 species recorded. Paradoxically perhaps, while the group is called the cat shark family, many species are commonly called dogfish. Recent DNA analysis have shown this group to be more closely related to batoids than to other sharks.

The cat shark is found in temperate and tropical seas worldwide, ranging from very shallow intertidal waters to depths of 2,000 metres (6,600 ft) or more, depending on species.

Description

Cat sharks may be distinguished by their elongated cat-like eyes and two small dorsal fins set far back. Most species are not particularly large, with lengths up to 60 - 70 cm or so, although the humpback cat shark, Apristurus gibbosus, from the deep waters of the South China Sea has been recorded at 4 m in length. Most of the species have a patterned appearance, ranging from stripes to patches to spots. They feed on invertebrates and smaller fish. Some species are ovoviviparous, but most lay eggs in tough egg-cases with curly tendrils at each end, known as mermaid's purses.

The "swell sharks" of the genus Cephaloscyllium have the curious ability to fill their stomachs with water or air when threatened, increasing their girth by a factor of 2 or 3.

Aquaria

The Australian marbled catshark, Atelomycterus macleayi, is a favored type for home aquaria, because it rarely grows to more than 60 centimetres (2.0 ft) in length. The coral catshark, however, is the most common scyliorhinid in home aquaria.