Hydrolycus

Hydrolycus is a genus of large dogtooth characins from tropical South America, where found in the Amazon and Orinoco basins, as well as rivers of the Guianas.^[1] The genus includes the largest dogtooth characins, reaching up to 1.17 m (3.8 ft) in length.^[1] They have long, pointed teeth (shorter and less extreme in H. wallacei) used for spearing their prey, generally smaller fish.^[2] In a study of the stomachs of 45 individuals, most were empty, but among the remaining the prey fish were 15–50% of the length Hydrolycus itself.^[3]

Hydrolycus
Hydrolycus scomberoides
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Characiformes
Family:	Cynodontidae
Genus:	Hydrolycus (J. P. Müller & Troschel, 1844)

In 1999 two new species were described, the first in this genus in 158 years.^[1][2]

Species

Hydrolycus armatus

There are currently four described species.^[1]

• Hydrolycus armatus (Jardine, 1841) (Payara)
• Hydrolycus scomberoides (G. Cuvier, 1819) (Payara)
• Hydrolycus tatauaia Toledo-Piza, Menezes & dos Santos, 1999
• Hydrolycus wallacei Toledo-Piza, Menezes & dos Santos, 1999