''Prosomyleus rhomboidalis'' is a medium to large omnivorous fish of the family

Serrasalmidae The Serrasalmidae (serrasalmids) are a family of characiform fishes native to freshwater habitats of South America. They include more than 90 species. The name means "serrated salmon family", which refers to the serrated keel running along the ...

from South America, where it is found in the Amazon River basin, as well as the north and the eastern

Guiana Shield The Guiana Shield (; ; ; ) is one of the three cratons of the South American Plate. It is a 1.7 billion-year-old Precambrian geological formation in northeast South America that forms a portion of the northern coast. The higher elevations on ...

rivers. It is the only species in the genus ''Prosomyleus''. It can grow to a length of . It was formerly placed in the genus '' Myleus'', of which it was thought to be the only member of its own subgenus, ''Prosomyleus''. It was upgraded to being a distinct genus in 2021.''''

References

*Planquette, P., P. Keith and P.-Y. Le Bail, 1996. Atlas des poissons d'eau douce de Guyane. Tome 1. Collection du Patrimoine Naturel Volume 22, MNHN, Paris & INRA, Paris. 429 p. Serrasalmidae Fish of the Amazon basin {{Characiformes-stub Monotypic ray-finned fish genera Characiformes genera Taxa named by Jacques Géry