Revision of the South American freshwater genus Plagioscion (Teleostei, Perciformes, Sciaenidae). Author Lilian Casatti text Zootaxa 2005 1080 39 64 http://www.zoobank.org/urn:lsid:zoobank.org:pub:11D3E992-6C7C-4A0B-8450-69B712B77C42 journal article z01080p039 [[ Genus Plagioscion Gill ]] Introduction The sciaenid genus Plagioscion Gill 1861 is endemic to South American fresh waters, where its members were originally distributed in the Rio Magdalena, Rio Amazonas, Rio Orinoco, lower Rio Parana basins and rivers of the Guianas (Casatti, 2003). Members of the genus have also been introduced into the upper Rio Parana and Rio Sao Francisco basins and in artificial reservoirs of northeastern Brazil. The monophyly of Plagioscion is supported by two characters (intercalar projecting downward and modified lateral-line scales [Sasaki, 1989]), and it is currently included in the subfamily Cynoscioninae. The systematics of Plagioscion is poorly understood, an unfortunate situation given the importance of the genus in subsistence and commercial fisheries. In this paper, the valid species of Plagioscion are revised and diagnosed, and an identification key is provided.