The narrowmouthed catshark (''Schroederichthys bivius'') is a

catshark Catsharks are ground sharks of the family Scyliorhinidae. They are the largest family of sharks with around 160 species placed in 17 genera. Although they are generally known as catsharks, some species can also be called dogfish due to previous n ...

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 ...

Scyliorhinidae, found from central

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 ...

around the

Straits of Magellan The Strait of Magellan (), also called the Straits of Magellan, is a navigable sea route in southern Chile separating mainland South America to the north and Tierra del Fuego to the south. The strait is considered the most important natural pass ...

, to

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

between

latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...

s 23° S and 56° S, at depths down to about in the Atlantic Ocean and about in the Pacific. It can grow to a length of up to . The reproduction of this catshark is

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

Description

As a juvenile, the narrowmouthed catshark is elongated and very slender, but as it grows its proportions change and it becomes rather more thickset. Its adult length can reach or more. The snout is rounded and slender and the front nasal flaps are narrow and lobed. This fish displays heterodont dentition; the mouth is long in both sexes, but is longer and narrower in males, with teeth that are twice the height of those of females. The general colour of the dorsal surface of both sexes is greyish-brown, with seven or eight dark brown saddles. Some large dark spots are scattered along the body but do not occur on the saddles. There are also many small white spots on the upper half of the body.

Distribution

The narrowmouthed catshark is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the coasts of South America, between

s 23° S and 56° S. In the southwestern Atlantic Ocean its range extends from southern Brazil, southwards to the

Beagle Channel Beagle Channel (; Yahgan: ''Onašaga'') is a strait in the Tierra del Fuego Archipelago, on the extreme southern tip of South America between Chile and Argentina. The channel separates the larger main island of Isla Grande de Tierra del Fuego fr ...

and in the southeasterly Pacific Ocean, southwards from northern Chile. Its depth range is from the surface down to about in the Atlantic Ocean and about in the Pacific.

Ecology

The narrowmouthed catshark is a

demersal The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

fish, feeding mostly on crustaceans and some fish. In the Beagle Channel in the summer it has been found to feed almost exclusively on the

squat lobster Squat lobsters are dorsoventrally flattened crustaceans with long tails held curled beneath the cephalothorax. They are found in the two superfamilies Galatheoidea and Chirostyloidea, which form part of the decapod infraorder Anomura, alongside ...

Munida gregaria ''Munida gregaria,'' commonly known as the gregarious squat lobster, is a species of squat lobster found along the eastern seaboard of the South Island of New Zealand, around the southern coast of Tasmania and in a few locations around the sou ...

'', but in other places its diet is more varied. The females are oviparous, the eggs being laid in egg cases which are attached to the seabed in estuaries and sheltered waters by tendrils. The newly hatched juvenile fish use these sheltered areas as nurseries.

Status

The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed this species as "least concern". *

References

{{DEFAULTSORT:catshark, narrowmouthed narrowmouthed catshark Fish of Chile Fish of Argentina Fauna of Temperate South America Taxa named by Johannes Peter Müller Taxa named by Friedrich Gustav Jakob Henle narrowmouthed catshark