The redeye piranha (''Serrasalmus rhombeus''), also known as the black piranha, white piranha, spotted piranha or yellow piranha, is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

, a

piranha A piranha or piraña (, , or ; or , ) is one of a number of freshwater fish in the family Serrasalmidae, or the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes. These fish inhabit South American rivers, ...

from 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 ...

Serrasalmidae The Serrasalmidae (serrasalmids) are a family of characiform fishes, recently elevated to family status. It includes more than 90 species. The name means "serrated salmon family", which refers to the serrated keel running along the belly of these ...

. It is found in northern South America. It is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the

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 ...

Serrasalmus ''Serrasalmus'' is a genus of piranhas. They are collectively known as pirambebas; the "typical" piranhas like the piraya piranha are nowadays placed in ''Pygocentrus''. Like all piranhas, ''Serrasalmus'' are native to South America. These fish ...

''.

Description

The redeye piranha is one of the larger species of piranha. It has a distinctively, rhombus-shaped body, solidly coloured from grey through to nearly black. Whatever the body colour, this species has red eyes. The colour of juveniles can be more mottled than in adults. As they mature their silvery body becomes less mottled and changes to a darker grey or black colour. How dark the fish become depends on the local water conditions; fish in Peru appear to be the darkest and may be almost jet black. The maximum recorded

fish measurement 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 ...

standard length is , although a more normal length is around , and they attain a maximum weight of .

Distribution

The redeye piranha is found in northern South America, east of the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

. They are found in the drainage systems of the

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...

and

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wor ...

as well as the

Essequibo River The Essequibo River (Spanish: ''Río Esequibo'' originally called by Alonso de Ojeda ''Río Dulce'') is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil–Guyana bor ...

and other rivers of the

Guiana Shield The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a ...

and the coastal rivers of northeastern Brazil. It has been introduced to

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

but is now

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

Habitat and biology

The redeye piranha occurs in a wide variety of habitats but the adults have a preference for the larger, deeper river channels where they normally hunt for prey either in deep stretches or in the vicinity of rapids. The juveniles are most frequently recorded in stiller stretches where there is thick submerged or marginal vegetation. Paler coloured fish tend to be found in turbid white waters, while in clear or dark waters, dark fish predominate. These fish are opportunistic and

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

feeders which will eat plants, fallen fruits and animals smaller than themselves such as insects and small fishes. They will also eat the scales and fins which they can nip off other fishes. They are well known scavengers, and feed on carcasses within the river. This is not a sociable species and normally lives solitarily. At least when breeding they defend an area around the nest which is placed among thick vegetation.

Taxonomy

The redeye piranha was first formally described in 1766 as ''Salmo rhombeus'' with the type locality given as

Brokopondo Brokopondo is the capital town of the Brokopondo District, Suriname. It is located on the west shore of the Suriname river, just north of the Afobaka dam. Brokopondo can be reached via the Afobakaweg from Paranam to Afobaka. Nearby is a granite mo ...

on the

Suriname River The Suriname River (Dutch: ''Surinamerivier'') is 480 km long and flows through the country Suriname. Its sources are located in the Guiana Highlands on the border between the Wilhelmina Mountains and the Eilerts de Haan Mountains (where it i ...

in Surinam. When

Bernard Germain de Lacépède Bernard-Germain-Étienne de La Ville-sur-Illon, comte de Lacépède or La Cépède (; 26 December 17566 October 1825) was a French naturalist and an active freemason. He is known for his contribution to the Comte de Buffon's great work, the ...

created the genus ''

'' in 1803 the only species he placed in it was ''Salmo rhombeus'', so this species is the type species of its genus. The morphological differences between populations suggest that ''S. rhombeus'' is a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, but molecular work to confirm this has yet to be undertaken.

References

{{Taxonbar, from=Q2038575 Serrasalmidae Piranhas Fish of South America Fish described in 1766 Taxa named by Carl Linnaeus