Hydrolycus tatauaia is a species of dogtooth characin found in the Amazon, Orinoco and Essequibo basins in tropical South America.[1] Adults mainly occur in deep and/or fast-flowing rivers.[2] It is migratory, moving upstream to breed in November–April.[3]
Like other Hydrolycus species, H. tatauaia has long pointed canine teeth that are used to spear their prey, generally smaller fish.[3] The body and head are silvery, and there is a vertically elongated dark spot behind the opercle. The tail is reddish to orange.[1] [3] [4] The species name tatauaia is of Tupi origin and means "fire tail".[1] [5] It reaches up to in total length and in weight.
This predatory fish occasionally makes its way into the aquarium trade, but it requires a very large tank.[3]