The riverine thruway hypothesis: rivers as a key mediator of gene flow for the aquatic paradoxical frog Pseudis tocantins (Anura, Hylidae)

FONSECA, EMANUEL M.; GARDA, ADRIAN A.; OLIVEIRA, ELIANA F.; CAMURUGI, FELIPE; MAGALHÃES, FELIPE DE M.; LANNA, FLÁVIA M.; ZURANO, JUAN PABLO; MARQUES, RICARDO; VENCES, MIGUEL; GEHARA, MARCELO

LANDSCAPE ECOLOGY

SPRINGER

Lugar: Berlin; Año: 2021

0921-2973

Context Rivers, landscape, and climate can alterpatterns of gene flow and consequently, shapeintraspecific genetic variation. While rivers are predictedto halt gene flow in terrestrial species, they mayfacilitate migration for aquatic species. Amphibiansare usually seen as water-dependent, yet multiplestudies have indicated that rivers exert a barrier effecton these organisms.Objectives In this study, we investigated the effectsof rivers and other abiotic factors, such as climate andgeography on genetic variation of a highly aquatic frog(Pseudis tocantins) inhabiting central Brazil.Methods We sequenced fragments of one mitochondrialand two nuclear genes of 179 individuals of P.tocantins from 19 localities along the Tocantins-Araguaia Basin in Brazil and used GeneralizedDissimilarity Modeling (GDM) to test the role ofrivers, landscape, and climate features on its geneticdifferentiation. Next, we tested three scenarios ofmigration along the Tocantins-Araguaia Basin usingapproximate Bayesian computation (ABC).Results We found that genetic differentiation amonglocalities is mostly explained by the influence of riverconnectivity. Conversely, elevation, slope, and pastand current climate have little or no impact on geneticdifferentiation. Furthermore, our results show thatpatterns of migration took place directionally, fromupstream to downstream sites.Conclusions Rivers have shaped patterns ofintraspecific diversity in P. tocantins by acting as themost important facilitator of gene flow. Therefore, wesuggest that future research should include the role ofrivers as a facilitator of gene flow, especially for thosespecies that are associated with aquatic environments