Population genetics of three threatened catfish species in heterogeneous environments of the Cauca River, Colombia

Abstract

Neotropical catfishes Ageneiosus pardalis, Pimelodus grosskopfii and Sorubim cuspicaudus are migratory fishes of commercial importance that exhibit decreasing populations due to overfishing and other anthropic interventions. This study used species-specific microsatellite loci to test the hypothesis that threatened fish populations show genetic vulnerability signs and are genetically structured in the middle and lower sections of the Cauca River. The studied species exhibit genetic diversity levels higher than the average values reported for Neotropical Siluriformes; however, they seem to have suffered recent bottlenecks and they present significant endogamy levels that are higher for the critically endangered catfish P. grosskopfii. Furthermore, both Ageneiosus pardalis and S. cuspicaudus are each formed by one genetic group, while Pimelodus grosskopfii comprises two coexisting genetic groups. The information obtained in this study is useful for the decision making in management plans that are appropriate for the sustainability of these three species populations within the proposal for the expansion of the hydroelectric development and other anthropic activities.

Multilocus approach reveals distinct evolutionary units of the South American apapa Pellona flavipinnis (Valenciennes, 1837) (Clupeiformes, Pristigasteridae)

“…The present study shows a certain degree of population genetic structure between lineages of P. flavipinnis within the Amazon basin, but without the presence of physical barriers that could limit gene flow. This scenario is similar to that found for two coexisting lineages of Brycon hilarii in the Miranda River in the Paraguai River basin (Sanches & Galetti Jr., 2007); for Brycon lundii (Wasko & Galetti Jr., 2002, 2003) and Prochilodus costatus (Braga‐Silva & Galetti, 2016), both in the São Francisco River basin, and for Pimelodus grosskopfii from the Cauca River in the Magdalena River basin (Restrepo‐Escobar et al ., 2021). In these studies, some authors indicate that the structure of co‐occurring populations is maintained due to the co‐migration of different stocks of the same lineage with genetic differences between populations during the reproductive period ( B. hilarii and B. lundii ).…”