
Rogério Santos Pereira
Publicado dia 21 de mai de 2021 às 15:36
Neutral evolutionary processes played a major role in the Amazonian Teleostean diversification
Title: Neutral evolutionary processes played a major role in the Amazonian Teleostean diversification: Unravelling Mesonauta festivus phylogeographic history

Author: NICOLAS LEROUX
Position: Master’s student – Laval University (Canadá)
Funding: NSERC Discovery
grant, NSERC CGS M grant, Ressources Aquatique
Quebec, FRQNT, Laval University, INCT ADAPTA II grants and the André
Darveau Grant.
Note[1]
Abstract
Amazonia is characterized by very heterogeneous riverscapes dominated by
three drastically divergent water types: black (ion-poor and acidic), white-
(nutrient-rich and turbid) and clear- (high transparency) waters. Recent
phylogeographic studies have associated the ecotone formed by these
environments to an ecologically driven speciation in fish species. With the
objective of understanding the evolutive forces behind the Amazonian Teleostean
diversification, we sampled 300 Mesonauta festivus (Figure 1) from 15
strategically positioned sites of the different water types already described
for Amazonia. Our genetic dataset of 56,090 SNPs is contrasting with previous
results and supports a low influence of water types on evolutionary processes.
Conversely, we detected strong influences of past events of vicariance
associated with the Amazon river formation and salt-water incursions since 2.5
Ma. While ecological speciation admittedly played a role in Amazonian fish’s
diversification, we argue that past isolation by geological processes mainly
explains the divergence in M. festivus populations. These major evolutive
processes potentially played a central role in the Amazonian fish diversity
genesis.
Figure 1. Master’s student Nicolas Leurox with a mesonauta specimen. Source: François-Etiénne
Sylvain.
[1]Reviewers: Ph.D students Jonatas da Silva
Castro and Samara Santos de Souza.
Editor: Ph.D. student Renan Diego Amanajás
Lima da Silva.