''Graus nigra'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea chub The sea chubs, also known as rudderfish and pilot fish and in Hawaiian as ''enenue'' or ''nenue'', are a family, Kyphosidae, of fishes in the order Perciformes native to the Atlantic, Indian and Pacific Oceans usually close to shore in marine w ...

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

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 ...

coast of South America, ranging from

Valdivia Valdivia (; Mapuche: Ainil) is a city and commune in southern Chile, administered by the Municipality of Valdivia. The city is named after its founder Pedro de Valdivia and is located at the confluence of the Calle-Calle, Valdivia, and Cau-Cau R ...

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 ...

to southern

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 ...

. This species grows to a

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of . It is popular as a

game fish Game fish, sport fish or quarry refer to popular fish pursued by recreational anglers, and can be freshwater or saltwater fish. Game fish can be eaten after being caught, or released after capture. Some game fish are also targeted commerciall ...

. This species is the only known member of its

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 ...

, and is known locally as ''vieja negra'' (meaning “old black” in Spanish).

Ecology

''Graus nigra'' is found in Chile and Peru, often in

forests A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

giant kelp ''Macrocystis pyrifera'', commonly known as giant kelp or bladder kelp, is a species of kelp (large brown algae), and one of four species in the genus ''Macrocystis''. Despite its appearance, it is not a plant; it is a heterokont. Giant kelp is ...

. Associated with it in this habitat are the Chilean abalone (''Concholepas concholepas''),

keyhole limpet Fissurellidae, common name the keyhole limpets and slit limpets, is a taxonomic family of limpet-like sea snails, marine gastropod molluscs in the clade Vetigastropoda.Rosenberg, G. (2012). Fissurellidae. Accessed through: World Register o ...

s (''Fissurella'' spp.), the Chilean sea urchin ''

Loxechinus albus ''Loxechinus albus'' is an echinoderm of the family Parechinidae, native to coastal southern South America, ranging from Ecuador, along the entire coasts of Peru and Chile, to Argentina, as well as the Falkland Islands. It is the only species in ...

'', and the labrid fish Galápagos sheephead (''Semicossyphus darwini''). Other carnivorous fish in the kelp forest include the Peruvian morwong (''Cheilodactylus variegatus''), the Chilean sandperch (''Pinguipes chilensis'') and the Cape redfish (''Sebastes capensis''); also present in this habitat is the herbivorous ''

Aplodactylus punctatus ''Aplodactylus punctatus'', the Zamba marblefish, is a species of marine ray finned fish, one of the marblefishes belonging to the family Aplodactylidae. It is found in the eastern Pacific Ocean of the west coast of South America. Taxonomy ''A ...

''. These fish are present in the dense lower storey of the kelp forest where they feed on the

benthos Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.Medialuna ancietae ''Medialuna ancietae'' is a species of sea chub native to the Pacific coast of South America where it inhabits the giant kelp forests. It is known locally as ''acha'', ''mero del sur'' or ''chino''. Description Sea chubs are medium-sized fish w ...

'', once abundant, has become so rare that most younger spear-fishers have never seen one. These changes in abundance of some of the dominant carnivorous fish in the giant kelp forest has had a marked effect on the biodiversity of their habitats.

References

{{Taxonbar, from=Q2192486 Kyphosidae Monotypic fish genera Western South American coastal fauna Fish of Chile Fish of Peru Fish described in 1887 Taxa named by Rodolfo Amando Philippi