The payara, ''(Hydrolycus scomberoides)'', is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of dogtooth tetra. This predatory fish is found in the

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

in tropical South America. It was the first of four species to be described in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'' Hydrolycus''.

Description

The most noticeable feature of ''H. scomberoides'' is the two long fangs protruding from its lower jaw. These are used to impale their prey, mostly smaller fish. It typically reaches a

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

of about , but can reach up to . There are reports of far larger individuals, up to in total length and in weight, based on records by

IGFA The International Game Fish Association (''IGFA'') is the leading authority on angling pursuits and the keeper of the most current world record fishing catches by fish categories. Fishermen who are sport fishers and anglers are careful to follow ...

, but this likely involves confusion with the related '' H. armatus''. ''H. scomberoides'' is overall silvery with a dark spot behind the opercle and another at the lower base of the

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

. In adults the tail is dusky on the basal half, turning paler (more transparent) towards the tip.

In the aquarium

The payara, which is also sold as the saber tooth barracuda, vampire fish, vampire tetra, or saber tusk barracuda, is a popular species for large, aggressive aquariums. It requires a large aquarium and can only be mixed with relatively large species, as smaller will be seen as potential prey.

References

{{Taxonbar, from=Q737277 Cynodontidae Game fish Fish of the Amazon basin Tetras of Brazil Freshwater fish of Colombia Fish described in 1819 Taxa named by Georges Cuvier