Patterns of population structure at microsatellite and mitochondrial DNA markers in the franciscana dolphin (Pontoporia blainvillei)

GARIBOLDI, MARÏ¿½A CONSTANZA; TÏ¿½NEZ, JUAN IGNACIO; FAILLA, MAURICIO; HEVIA, MARTA; PANEBIANCO, MARÏ¿½A VICTORIA; PASO VIOLA, MARÏ¿½A NATALIA; VITULLO, ALFREDO DANIEL; CAPPOZZO, HUMBERTO LUIS

Ecology and Evolution

John Wiley and Sons Ltd

Año: 2016 vol. 6 p. 8764 - 8776

The franciscana dolphin, Pontorporia blainvillei, is an endemic cetacean of the Atlantic coast of South America. Its coastal distribution and restricted movement patterns make this species vulnerable to anthropogenic factors, particularly to incidental bycatch. We used mitochondrial DNA control region sequences, 10 microsatellites, and sex data to investigate the population structure of the franciscana dolphin from a previously established management area, which includes the southern edge of its geographic range. F-statistics and Bayesian cluster analyses revealed the existence of three genetically distinct populations. Based on the microsatellite loci, similar levels of genetic variability were found in the area; 13 private alleles were found in Monte Hermoso, but none in Claromec�. When considering the mitochondrial DNA control region sequences, lower levels of genetic diversity were found in Monte Hermoso, when compared to the other localities. Low levels of gene flow were found between most localities. Additionally, no evidence of isolation by distance nor sex-biased dispersal was detected in the study area. In view of these results showing that populations from Necochea/Claromec�, Monte Hermoso, and R�o Negro were found to be genetically distinct and the available genetic information for the species previously published, Argentina would comprise five distinct populations: Samboromb�n West/Samboromb�n South, Cabo San Antonio/Buenos Aires East, Necochea/Claromec�/Buenos Aires Southwest, Monte Hermoso, and R�o Negro. In order to ensure the long-term survival of the franciscana dolphin, management and conservation strategies should be developed considering each of these populations as different management units.