Comparative conservation genetics of giant and
Neotropical otters in the Central Amazon Basin

Abstract

Genetic diversity provides adaptive potential, which is crucial for the long-term persistence of species, allowing them to respond to disturbances and environmental changes. Quantifying genetic diversity and understanding how it emerges in natural populations are therefore important objectives towards conserving biodiversity.
Giant otters (Pteronura brasiliensis) and Neotropical otters (Lontra longicaudis) are widespread in Amazonia, but intensification of anthropogenic interference in this biome is increasingly threatening these species. Both species are under a pressing need for more local and regional scale research on their population trends, spatial patterns and genetic structure. Information on population trends and spatial patterns informs about the mechanisms driving the evolution of genetic structure. In order to contribute to expanding this knowledge, nuclear and mitochondrial DNA markers and a habitat modelling approach were employed in a comparative conservation genetics study at a regional scale in Central Amazonia.
The central goal was to assess patterns of habitat use, genetic diversity and population structure, in order to gain insight into the current levels of gene flow and connectivity among populations, and the relevant evolutionary mechanisms. Specific aims included assessing if population structure could reflect intrinsic species attributes such as sociality and behavioural ecology as well as habitat features, which can act in the promotion or limitation of gene flow.
Despite a high potential for structural connectivity and dispersal along the hydrographic network, the results indicated the existence of genetically distinct clusters of otter populations over the spatial scale considered. This type of pattern has not been detected for either species until now, and outcomes from this research provide novel information that can provide transferrable inference to the conservation and management of otters and other semi-aquatic Amazonian vertebrates.