Phylogenetic relationships of the species of Plagioscion Gill, 1861 (Eupercaria, Sciaenidae).

The genus PlagioscionGill, 1861 (Sciaenidae; Eupercaria) is currently composed of five valid species (P. squamosissimus, P. auratus, P. magdalenae, P. ternetzi and P. montei) widely distributed in South America. This study seeks to test the monophyly of Plagioscion and develope an hypothesis of phylogenetic relationships among the species of the genus, based on the analysis of 28 characters of external and internal morphology and behavior. The ingroup consists of the five species of Plagioscion. The outgroup was composed of eight species of the genera Ctenosciaena, Cynoscion, Isopisthus, Larimus, Macrodon and Pachyurus. Cladistic analysis yielded a single most parsimonious cladogram (L = 50, CI = 0.60 and RI = 0.72). The monophyly of genus Plagioscion was supported by the presence of five synapomorphies, corroborating previous studies. The single most parsimonious cladogram recovered the following hypothesis of relationships among the species of the genus: ((P. squamosissimus + P. ternetzi) (P. magdalenae (P. montei + P. magdalenae))). Comments about all characters are presented.