Moenkhausia Copei is a peaceful community fish. They can reach a length of about 6 to 7 centimetres. They have an elongated shape and a red tail- and adipose fin. In some fish the dorsal fin can show some colouring but usually they are transparent just as the pectoral, pelvic and anal fin.
This species has been described by Steindachner in 1882.
Synonym: Tetragonopterus copei.
They are common to a large area in the river basin of the Amazon and Rio Orinoco river. Due to this large habitat, variations of the species have emerged in colour and brightness of those colours within the species. The pictures below show the difference between a specimen from Venezuela, which displays bright red colouring, and a specimen from Peru which has a less bright colouring (light orange).
Moenkhausia copei seems to be an elongated version of the Moenkhausia colletti. With the copei, the colouring is a deeper tone of red and there is no visible shoulder spot. This spot does occur with males around spawning. The difference between the two species is best deducted from the shape of the body.