Systematic revision of the South American silversides (Teleostei, Atheriniformes).

The taxonomic and systematic history of the South American silversides has changed significantly since Campos (1984) review. As a result of phylogenetic studies of the subfamilies Menidiinae (Chernoff, 1986b), Atherinopsinae (White, 1985; Crabtree, 1987; Dyer 1997, 1998) and of the order Atheriniformes (Saeed et al., 1994; Dyer and Chernoff, 1996) the taxonomy and classification of silversides has changed notoriously (Table I). Two systematic studies with different methodologies and divergent results in many ways coincided in that the subfamilies Menidiinae and Atherinopsinae, traditionally considered as atherinids, were to form part of the family Atherinopsidae (Saeed et al., 1994; Dyer and Chernoff, 1996). The purpose of this paper is to review the present state of the systematics (taxonomy, relationships and distribution) of the South American silversides in the context of phylogenetic revisions of Atheriniformes and Atherinopsinae. All systematic results presented herein are based on published material (Dyer and Chernoff, 1996; Dyer, 1993, 1997, 1998, 2000, 2003a,b; Dyer and Gosztonyi, 1999; Malabarba and Dyer, 2002). In addition to some diagnostic features of the taxa involved (genera, tribes, subfamilies, and families), an identification key and some identification and diagnostic problems, are presented.