DIAZ DE ASTARLOA Juan Martin
congresos y reuniones científicas
DNA Barcoding Neotropical fishes:news from the Pampa plain, Argentina
ROSSO, J.J.; MABRAGAÑA E.; GONZÁLEZ CASTRO, M.; DÍAZ DE ASTARLOA, J. M.
Congreso; First World Fish Barcode of Life Congress; 2012
DNA barcode has been able to separate c. 93% of already described freshwater fish species. Nevertheless, many freshwater fish species of southern South America are yet to be barcoded. Particularly, the Neotropical fish fauna living in Argentina is yet to be barcoded. In this paper, the fish fauna of the Pampa Plain, the southernmost extreme in the distribution range of many Neotropical species is surveyed in order to obtain their COI sequences and evaluate the efficiency of DNA barcode to discriminate among species. Our results demonstrate that barcoding is an efficient tool for species identification of freshwater fishes of the Pampa Plain, Argentina. In the NJ/K2P tree, all members of a given genus clustered together. The use of 190 COI sequences from 36 putative species allowed us to further discriminate among all species. Nevertheless, deep intra-specific divergences were detected. Surprisingly, species such as Cnesterodon decemmaculatus, Bryconamericus iheringii and Salminus brasiliensis showed individuals with a divergence of 2.4, 5 and 6 % respectively from its conspecifics. On the other hand, two morphologically and meristic different species of the genus Astyanax showed a very low (0.62%) congeneric divergence. Our results also showed that Pampa Plain representatives of Salminus brasiliensis, Rhamdia quelen, Hoplias malabaricus, Synbranchus marmoratus, Australoheros facetus, Oligosarcus jenynsii and Corydoras paleatus differed by more than 3% from their conspecifics of other regions of South America. The present study is the first assessing the efficiency of barcoding for the freshwater fishes of Argentina. It allowed us to flag three possible cryptic species and also highlighted a strong geographic structure in the COI sequences composition of seven species of South America.