Redhook Metynnis

The red hooked anal fin of the female is actually a plough. The male has a bilobed anal fin which is designed to wrap around the female's "hook". During spawning, the female inserts the hook into the substrate (e.g., gravel) and ploughs a furrow while laying the eggs with the male in a position next to her with his bi-lobed fin wrapped around the hook as he fertilises the eggs. The female's "hook" is suprisingly strong and can be pushed into coarse gravel (up to the anal opening) without any problem with a shaking body action, the male's bilobed hook folds under the same pressure so they can work in unison (Ref. 55767).

Gregarious and non-aggressive (Ref. 27188). Prefers calm zones of main rivers where the vegetation hangs over the river banks. Feeds on the leaves of river plants (Ref. 12225). Possesses powerful dentition that can cause serious bites. Its reproduction has not yet been carried out in captivity (Ref. 27188).

fisheries: minor commercial; aquarium: commercial

The redhook myleus, Myloplus rubripinnis, is a medium to large omnivorous fish of the family Serrasalmidae from South America, where found in the Amazon and Orinoco basins, as well as rivers of the Guiana Shield. It is peaceful and schools often, and can grow to a length of 39 cm (15 in). They are also called the redhook silver dollar and are one of the fish referred to as "silver dollars". These fish are capable of delivering serious bites to humans.