Wolf Fishes

The red wolf fish, Erythrinus erythrinus, is a predatory erythrinid from Peru, French Guiana, Venezuela, Trinidad and Tobago and Brazil. Colour and pattern vary with collection locality, and genetic differences between populations suggest it is a species complex. A modified swim bladder lets it breathe in oxygen-deficient, stagnant water. It is very intolerant of conspecifics, often fighting them to the death, and will strike at nets and siphon tubes with its sharp teeth.

The gold wolf fish, Hoplerythrinus unitaeniatus, is a predatory erythrinid widespread throughout much of South America. Also known as the golden trahira, it inhabits small tributaries, swamps, marshes and forest lake margins, and can breathe air using a modified swim bladder. The only member of its genus to appear in the trade with any regularity, it is really a fish for the specialist and is intolerant of conspecifics.