Phylogeography of Cnesterodon decemmaculatus (Cyprinodontiformes: Poeciilidae) in Southern Pampas, Argentina: ancient versus recent patterns in freshwater fishes

BRUNO CECILIA; MALPELI FERNANDO ; CASCIOTTA JORGE; ALMIRON ADRIANA; LIZARRALDE MARTA .

ENVIRONMENTAL BIOLOGY OF FISHES

SPRINGER

Lugar: Berlin; Año: 2015

0378-1909

The Southern Pampean Area includes the southernmost limit of the Brazilian subregion and represents an interesting model to study how evolution of the landscape has affected the distribution of freshwater fishes in time and space. The hydrogeographic pattern of the region results from a combination of factors including climatic and sea level changes occurred since the Miocene and extending into the Quaternary. The hydrologic basins of this region are isolated, with similar ichthyological composition. Here we use a phylogeographic approach to infer how paleoclimatic changes affected the distribution of genetic variation in freshwater fishes. We analyzed the control region of mtDNA of Cnesterodon decemmaculatus and compared it with published data for Jenynsia multidentata in the same area. C. decemmaculatus showed two main groups with scarce divergence and wide geographical distribution within the area.The low divergence found between the C. decemmaculatus haplotypes could suggest that its history in the area is relatively recent. The presence of C. decemmaculatus in the area appears to have a recent demographic history, in contrast with the pattern reported for J. multidentata. These results could be due to different responses of each species to the diverse environments resulting from geologic and paleoclimatic changes occurred in the region.