Common name: Black Sharks, Kitefin Sharks, Seal Sharks



Small to medium-sized deepwater sharks with two dorsal fins that lack spines (except Squaliolus), no anal fin, a narrow cone-shaped head, large spiracles and a subterminal notch on the caudal fin; body cylindrical in cross-section. Kitefin sharks have strong jaws with small daggerlike teeth in the upper jaw, and laterally expanded lower jaw teeth with high-bladelike crowns.

Some species are bioluminescent, and the genus Squaliolus contains the smallest known shark, Squaliolus laticaudus.

Cite this page as:
Dianne J. Bray, Kitefin Sharks, DALATIIDAE in Fishes of Australia, accessed 06 Jun 2023,

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Family Taxonomy

The family comprises 7 genera (5 of which are monotypic) and 10 species worldwide. Four genera and five species occur in Australian waters.

Kitefin sharks of the family Dalatiidae (Squaliformes) comprise 7 genera (Dalatias, Euprotomicroides, Euprotomicrus, Heteroscymnoides, Isistius, Mollisquama, and Squaliolus) of which five are monotypic–the highest percentage of monotypic genera for any family in the order Squaliformes (Ebert et al. 2013). Dalatiids are distinguished from other squaliform sharks by their snout shapes, , dorsal fins without spines (except Squaliolus), and the lack of an anal fin.

Family Distribution

Kitefin sharks are meso- to bathypelagic in continental shelf and slope waters of all oceans. Some species migrate to near surface waters at night.

Family Size

Range in length from 20cm to about 1.6 metres.

Family Reproduction

Species are aplacental viviparous (ovoviviparous), with embryos nourished in utero by a yolk sac. Females produce litters of up to 16 pups.

Some species are bioluminescent, which may be used as camouflage or counter-illumination, or to attract prey. 

Family Commercial

Although most species are too small to be of interest to fisheries, one species is commercially important.

Family Remarks

Species of the genus Isistius (cookie cutter sharks) have a unique feeding behaviour, and use their modified suction lips and cookie-cutter-like teeth to carve out an oval-shaped flesh plug from their prey, including marine mammals, tunas, billfishes, squids - and the odd unfortunate human.


Dianne J. Bray


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White, W. 2008. Shark Families Heterodontidae to Pristiophoridae. pp. 32-100 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.