The hooktooth dogfish, ''Aculeola nigra'', is a small, little-known dogfish, the only member of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Aculeola''. The type specimen is held at the National Natural History Museum,

Santiago Santiago (, ; ), also known as Santiago de Chile, is the capital and largest city of Chile as well as one of the largest cities in the Americas. It is the center of Chile's most densely populated region, the Santiago Metropolitan Region, whose ...

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

Description

The hooktooth dogfish has a blunt, flattened snout, very large eyes, a relatively long distance from the eye to the first gill slit, small grooved dorsal spines, a first dorsal fin about halfway between the pectoral and pelvic fins, and a broad caudal fin. They are black with a maximum length of only 60 cm.

Distribution

They are found in the eastern South

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

along the coast of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

from

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

to central

Habits and habitat

This shark is a little-known, yet common, shark that lives at depths between 110 and 560 m. They are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

, with at least three pups per litter. They probably eat

bony fish Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...

and

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

References

* * FAO Species Catalogue, Volume 4, Parts 1 and 2: Sharks of the World

External links

Species Description of Aculeola nigra at www.shark-references.com
{{DEFAULTSORT:Hooktooth dogfish Etmopteridae Fish described in 1959