Cottoperca Trigloides

''Cottoperca'' is a genus of marine ray-finned fishes belonging to the family Bovichtidae, the temperate icefishes or thornfishes. They are found in the southeastern Pacific, southwestern Atlantic and northern Southern Oceans off southern South America.

Taxonomy

''Cottoperca'' was first formally described as a genus in 1875 by the Austrian ichthyologist Franz Steindachner with ''Cottoperca rosenbergii'' which Steindachner described as its only species. ''C. rosenbergii w''as later found to be a synonym of ''Batrachus trigloides'' which had been described by the German naturalist Johann Reinhold Forster in 1801. Some taxonomic authorities consider that ''Cottoperca'' is monotypic and that the only valid species is ''C. gobio'', while others state the only valid species is ''C. trigloides'', although this is not the position taken by the 5th edition of Fishes of the World, World Register of Marine Species, FishBase or the Catalog of Fishes, which all give the genus 2 species. The genus name is made up from ''cottus'', meaning "sculpin" and ''perca'' which means "perch", an allusion Steindachner did not explain but which is probably a reference to the sculpin like shape of ''C. rosenbergii''.

Species

There are currently two recognized species in this genus:
* ''Cottoperca gobio'' ( Günther, 1861) (Channel bull blenny)
* '' Cottoperca trigloides'' ( J. R. Forster, 1801) (Frogmouth)

Characteristics

''Cottoperca'' species are larger than the related ''Bovichtus'' species, with a maximum total length of , and unlike them they are clothed in scales. The large head is bony with only weak spines on the operculum. There is a small fleshy tentacle above each eye. Like ''Bovichtus'' they have robust lower fin rays on the pelvic fin as an adaptation for gripping onto the substrate.

Distribution and habitat

''Cottoperca'' fishes are found in the waters off the southern cone of South America in the southwestern Atlantic around Cape Horn and Tierra de Fuego into the southeastern Pacific Ocean. Their range extends as far north as 41°S and south to 54°S. They can be found in shallow waters as well as in water that is hundreds of metres deep, although they are typically found at depths of .

Biology

''Cottoperca'' fishes are benthic ambush predators, feeding mostly on fish, small crustaceans and some algae. They have a high reproductive capacity and rates of growth which have enabled them to live on a large area of the Patagonian Shelf Studies performed in the Beagle Channel indicated that ''C. trigloides'' lives around the holdfasts in kelp forests dominated by ''Macrocystis pyrifera''. Although most of the prey of these fishes is benthic they are known to eat large amounts of the nectonic herring ''Sprattus fuegensis''. They lay egg masses which stick to the substrated. They are known to live for at least 8 years.

Fisheries and conservation

''Cottoperca'' are not utilized, but they commonly discarded as bycatch in hake and shrimp fisheries. This bycatch is not thought to threaten the population of ''C. trigloides'' which is classed as Least Concern by the IUCN.

References

{{Taxonbar, from=Q2049095

Bovichtidae