The southern sleeper shark or Whitley's sleeper shark (''Somniosus antarcticus'') is a deepwater benthopelagic sleeper shark of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Somniosidae The Somniosidae are a family of sharks in the order Squaliformes, commonly known as sleeper sharks. The common name ''"sleeper shark"'' comes from their slow swimming, low activity level, and perceived non-aggressive nature. Distribution and hab ...

found in the southern

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...

, and Pacific Oceans.

Taxonomy

It was formerly sometimes viewed as conspecific with either the

Greenland shark The Greenland shark (''Somniosus microcephalus''), also known as the gurry shark, grey shark, or by the Kalaallisut name ''eqalussuaq'', is a large shark of the family Somniosidae ("sleeper sharks"), closely related to the Pacific and southern s ...

(''Somniosus microcephalus''), or the

Pacific sleeper shark The Pacific sleeper shark (''Somniosus pacificus'') is a sleeper shark of the family Somniosidae, found in the North Pacific on continental shelves and slopes in Arctic and temperate waters between latitudes 70°N and 22°N, from the surface t ...

(''Somniosus pacificus'').

Habitat

It is known from depths of 400 to 1,100 m.

Description

Its length is up to . The southern sleeper shark differs from ''S. microcephalus'' in having more tooth rows in the lower jaw, a shorter interdorsal region, a more posterior first dorsal fin, and fewer precaudal vertebrae, and from both species in having lower dorsal fins.

Diet

It feeds primarily on

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s, especially squid- including the Giant and

colossal squid The colossal squid (''Mesonychoteuthis hamiltoni'') is part of the family Cranchiidae. It is sometimes called the Antarctic squid or giant cranch squid and is believed to be the largest squid species in terms of mass. It is the only recognize ...

s- and fish; its stomach contents also less commonly contain remains of marine mammals and birds. Based on its generally sluggish nature and the speed of its prey, it is thought to be an ambush predator. A long female caught off the coast of

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 ...

had a whole

southern right whale dolphin The southern right whale dolphin (''Lissodelphis peronii'') is a small and slender species of cetacean, found in cool waters of the Southern Hemisphere. It is one of two species of right whale dolphin (genus ''Lissodelphis''). This genus is char ...

in its stomach. This dogfish is sometimes taken as

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

in the

orange roughy The orange roughy (''Hoplostethus atlanticus''), also known as the red roughy, slimehead and deep sea perch, is a relatively large deep-sea fish belonging to the slimehead family (Trachichthyidae). The UK Marine Conservation Society has categoriz ...

and Patagonian toothfish fisheries; whether this poses a threat to the species is currently unknown.

Conservation status

In June 2018 the New Zealand

Department of Conservation An environmental ministry is a national or subnational government agency politically responsible for the environment and/or natural resources. Various other names are commonly used to identify such agencies, such as Ministry of the Environment ...

classified the southern sleeper shark as "Not Threatened" with the qualifiers "Data Poor" and "Uncertain whether Secure Overseas" under the

New Zealand Threat Classification System The New Zealand Threat Classification System is used by the Department of Conservation to assess conservation priorities of species in New Zealand. The system was developed because the IUCN Red List, a similar conservation status system, had some ...

. The IUCN also does not regard it as threatened, noting a widespread distribution and no indication of a declining population, but believes it is not naturally abundant and that much more data and understanding of its population, interactions and biology is needed.

References

{{DEFAULTSORT:Southern sleeper shark Somniosus Fish described in 1939 Fish of the Atlantic Ocean Fish of the Indian Ocean Fish of the Pacific Ocean Taxonomy articles created by Polbot