Family DALATIIDAE

Common name: Black Sharks, Kitefin Sharks, Seal Sharks

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Summary:

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.

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Cite this page as:
Dianne J. Bray, Kitefin Sharks, DALATIIDAE in Fishes of Australia, accessed 06 Jun 2023, https://fishesofaustralia.net.au/Home/family/255

More Info

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.

Author

 Dianne J. Bray

References

Claes, J.M., Nilsson, D.-E., Straube, N., Collin, S.P. & Mallefet, J. 2014. Iso-luminance counterillumination drove bioluminescent shark radiation. Scientific Reports 4: 1–7. Open access http://www.nature.com/srep/2014/140310/srep04328/full/srep04328.html

Compagno, L.J.V. & Niem, V.H. 1998. Hexanchidae, Echinorhinidae, Squalidae. pp. 1208-1232 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 2 687-1396 pp.

Compagno, L.J.V., Dando, M. & Fowler, S. 2005. A Field Guide to the Sharks of the World. London : Collins 368 pp.

Ebert, D.A., Fowler, S. & Compagno, L. 2013. Sharks of the World: A fully illustrated guide. Wild Nature Press, Plymouth, NH, 528 pp.

Gadig, O.B.F. & Gomes, U.L. 2002. First report on embryos of Isistius brasiliensis. Journal of Fish Biology 60: 1322–1325. Abstract http://dx.doi.org/10.1111/j.1095-8649.2002.tb01723.x

Honebrink, R., R. Buch, P. Galpin & G.H. Burgess. 2011. First documented attack on a live human by a Cookiecutter Shark (Squaliformes, Dalatiidae: Isistius sp.) Pacific Science 65(3): 365-374.

Last, P.R. & Stevens, J.D. 2009. Sharks and Rays of Australia. Collingwood : CSIRO Publishing Australia 2, 550 pp.

Shirai, S. 1992. Squalean Phylogeny. A new framework of "squaloid" sharks and related taxa. Sapporo : Hokkaido University Press 151 pp.

Shirai, S. & Nakaya, K. 1990. Interrelationships of the Etmopterinae (Chondrichthys, Squaliformes). 347-356 in Pratt, H.L. Jr, Gruber, S.H. & Taniuchi, T. Elasmobranchs as living resources: advances in the biology, ecology, systematics, and the status of the fisheries. NOAA Technical Report 90: 347-356

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.