The South American tropical fish genus Plagioscion has been revised and the number of species it contains has been dropped to five.
The revision, which was undertaken by Lilian Cassati of UNESP (Universidade Estadual Paulista, Laboratorio de Ictiologia) in Brazil, has just been published in the systematics journal Zootaxa and considers just five of the 15 nominal species as valid taxa.
According to Cassati, the genus Plagioscio should be restricted to just five species: Plagioscion squamosissimus which is found in most freshwater drainages on the eastern side of the Andes, P. auratus which is found in the Orinoco and Amazon basins, P. magdalenae which comes from the Rio Magdalena basin, P. ternetzi from the lower Parana, Paraguay and Uruguay basins and P. montei which is found in the Amazon basin.
The Plagioscion genus, which is a member of the family Sciaenidae, is found in freshwater but most other sciaenids are marine species.
Not that much is known about the genus, but it is believed to be a representative of the sciaenid Cynoscioninae subfamily.
Several species are commercially important as food fishes in South America.
For more details see the paper: Cassati, L. (2005) - Revision of the South American freshwater genus Plagioscion (Teleostei, Perciformes, Sciaenidae). Zootaxa, 1080: 39-64 (2005).