The anostomid fishes of the genus Laemolyta have been revised and five species have been recognised.
Kelly Cristina Mautari and Naercio Aquino Menezes revised the South American Laemolyta genus in the latest issue of the journal Neotropical Ichthyology and redefined the fish based on their study.
By studying the morphology, dentition and osteology of the species in the genus Mautari and Menezes were able to place some of the representatives into synonymy and clarify some of the taxonomic issues in some of the other species.
Laemolyta garmani macra was found to be a junior synonym of Laemolyta garmani, L. petiti was found to be a junior synonym of L. fernandezi and L. nitens and L. varia were both found to be synonyms of L. proxima.
This leaves five valid species in the genus: L. fernandezi, which is found in the Rio Orinoco and the Tocatins, Araguaia and Xingu basins; L. orinocensis, which is restricted to the Orinoco; L. taeniata, which is found in the Amazon basin and the Orinoco; and L. proxima and garmani, which both come from the Orinoco.
Mautari and Menezes said that the study was needed because the original descriptions of some Laemolyta weren't very precise and were often based on immature fish, which differ in their morphology from adults.
For more details on the revision see the paper: KC Mautari and NA Menezes (2006) - Revision of the South American freshwater fish genus Laemolyta Cope, 1872 (Ostariophysi: Characiformes: Anostomidae). Neotropical Ichthyology, 4(1):27-44, 2006.