DIAZ DE ASTARLOA Juan Martin
congresos y reuniones científicas
Barcoding the Fish Fauna of the Uruguay River Basin, South America
ROSSO, J.J.; MABRAGAÑA E.; GONZALEZ CASTRO M.; DELPIANI, S. M.; DÍAZ DE ASTARLOA, J. M.
Conferencia; 2nd World Fish Barcode of Life Conference; 2014
The Plata River Basin is the second largest drainage in South America after the Amazon . The La Plata River comprises four large sub-basins: Paraná, Paraguay, Uruguay and Plata Rivers. Ichthyofaunistic research is notoriously skewed since most efforts have been devoted to the Paraná River, the fish fauna of the Uruguay River being one of the poorest known so far. In this study we aimed to increase the knowledge about the richness of fish species in the Uruguay River by means of molecular analysis performed following the barcode protocol. We sampled 39 locations at middle and lower Uruguay River reaches, in Argentina. Our results revealed the occurrence of 92 different BINs grouped in seven orders, 26 families, and 52 genera. The COI sequence analyses and diagnostics revealed the existence of hidden diversity within some taxa previously supposed to be a unique taxonomic unit. Particularly, we detected two different BINs within emblematic species as Rhamdia quelen and Salminus brasiliensis, but also within the small Phalloceros caudimaculatus, the only species of this genus reported for Argentina. We also found strong evidence supporting the existence of two new species of the genus Hoplias. This was corroborated not only by a unique COI sequence among Hoplias specimens in the BOLD database, but also by means of meristic and morphometric analyses that unambiguously discriminated these putative new species from all other known species of Hoplias. Only one species within the genera Rhamdia and Salminus is reported for the Uruguay River basin in Argentina and both of them are subjected to be commercially exploited in the basin. Since we detected hidden diversity within these taxa, the possibility of overexploiting these resources can not be disregarded. Therefore, our results flag a very important task to be solved in order to properly manage and control the fishery effort exerted on these species.