The frog shark (''Somniosus longus'') is a very rare species of squaliform

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...

mainly found in deep water in the

Pacific Ocean 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 contin ...

. It is in the sleeper shark family

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 ha ...

with 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 souther ...

Description

The frog shark is known to grow to a maximum length of 110 cm in males and 130 cm in females. Previously classified in the same taxon as the similar '' Somniosus rostratus'', it is differentiated from ''S. rostratus'' in having a longer second dorsal fin, a slightly larger eye, more rows of teeth and a greater spiral valve count.

Range

Fewer than a dozen specimens of this deepwater shark have been collected, mostly from the

. The frog shark has been recorded off the coasts of Japan,

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

, and possibly Salas y Gómez, as well as the

Nazca Ridge The Nazca Ridge is a submarine ridge, located on the Nazca Plate off the west coast of South America. This plate and ridge are currently subducting under the South American Plate at a convergent boundary known as the Peru-Chile Trench at approx ...

, from as shallow as 120–150 m and as deep as 1,116 m.

Threats

The frog shark is occasionally caught by trawl, longline, and crab-pot fisheries. As of 2015, no current conservation efforts are in place. 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 frog shark as "Data Deficient" with the qualifier "Uncertain whether Secure Overseas" under the New Zealand Threat Classification System.

References

frog shark Fish of the Pacific Ocean Fish of Japan Fish of New Zealand frog shark Taxa named by Shigeho Tanaka {{shark-stub