Does Mugil liza Valenciennes 1836 (Teleostei: Mugiliformes) occur in Argentinean waters?

The present paper deals with the occurrence of two nominal species of Mugil (Mugil liza Valenciennes 1836 and Mugil platanus Günther 1880) in Argentinean waters. The investigation is necessary to clarify the distribution of these species before any regional study on the biology can be made. In Argentinean bibliographies, two members of the familiy Mugilidae are mentioned as living in Argentinean waters, M. liza Valenciennes 1836 and M. platanus Günther 1880, while recent revisions on the southwestern Atlantic members of this family recognised M. liza as living in the Caribbean and northern Brazil and M. platanus along the southern coast of Brazil and north of Argentina. Samples from six coastal localities and from a freshwater lagoon between 36 and 42ºS latitude, comprising a total of 369 individuals were examined and compared with Type specimens of both nominal species and a sample of 38 individuals of M. platanus from Río Grande do Sul, Brazil (32ºS). Morphometric and meristic data were recorded: morphometrics was analyzed by normalization of the individuals of each locality followed by principal component analysis and meristics were compared with the values from Types and fresh specimens corresponding to M. platanus and M. liza. The comparative analysis indicated that M. liza does not occur in Argentinean waters, being M. platanus the only permanent present species.