''Hydrolycus tatauaia'' 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 ...

dogtooth characin Cynodontidae, also known as dogtooth characins or vampire tetras, are a family of predatory, characiform freshwater fishes from South America. This group is not very diverse, and includes only five genera and 14 species. Most of what is known abo ...

found in 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 ...

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 ...

and

Essequibo Essequibo is the largest traditional region of Guyana but not an administrative region of Guyana today. It may also refer to: * Essequibo River, the largest river in Guyana * Essequibo (colony), a former Dutch colony in what is now Guyana; * Esseq ...

basins in tropical South America. Adults mainly occur in deep and/or fast-flowing rivers. It is migratory, moving upstream to breed in November–April. Like other '' Hydrolycus'' species, ''H. tatauaia'' has long pointed canine teeth that are used to spear their prey, generelly smaller fish. The body and head are silvery, and there is a vertically elongated dark spot behind the

opercle The operculum is a series of bones found in bony fish and chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. Anatomy The opercular series contains four bon ...

. The tail is reddish to orange. The species name ''tatauaia'' is of

Tupi Tupi may refer to: * Tupi people of Brazil * Tupi or Tupian languages, spoken in South America ** Tupi language, an extinct Tupian language spoken by the Tupi people * Tupi oil field off the coast of Brazil * Tupi Paulista, a Brazilian municipalit ...

origin and means "fire tail". It reaches up to in

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 ...

and in weight. This predatory fish occasionally makes its way into the aquarium trade, but it requires a very large tank.

References

{{Taxonbar, from=Q6408345 Cynodontidae Freshwater fish of Brazil Freshwater fish of Colombia Fish of Guyana Fish of Venezuela Fish of the Amazon basin Taxa named by Naércio Aquino de Menezes Fish described in 1999