The Meeting of Waters, a possible shelter of evolutionary significant units for Amazonian fish

Alba Ardura,Vanessa Gomes,Jose L Horreo,Eva Garcia-Vazquez,Ana R Linde,Josino C Moreira

doi:10.1007/s10592-013-0505-8

Abstract

Identification of priority conservation areas is crucial for safeguarding freshwater ecosystems. Occurrence of unique populations and/or evolutionary significant units for key species is one of the most frequent reasons for protecting a region or location. In this study we have studied two of the most important fisheries resources of the Amazon basin, Curimata and Tambaqui, from different areas, in order to identify common zones of special diversity. Employing the Barcoding cytochrome oxidase I gene as a genetic tool, we have detected a clear differentiation of the populations inhabiting the Meeting of Waters and the rest of the basin for both species. This area corresponds to the confluence of the Solimoes and the Negro rivers, of different physicochemical water characteristics, at the Brazilian city of Manaus in central Amazonas. The Meeting of Waters area (near Manaus) could be recommended as a potential area subject of special management, given its apparent role as a shelter for evolutionary significant units.

Highlights

The Amazon exhibits all the principle features associated with aquatic species richness globally (Albert and Reis 2011)
Here we have investigated the level of population differentiation between the rivers confluence and other upstream and Prochilodus nigricans Colossoma macropomum downstream areas, based on variation at the Barcoding COI mitochondrial sequence (Ward et al 2005)
The Meeting of Waters sample exhibited lower haplotype diversity than the rest of the river areas, but the nucleotidic diversity was similar

Summary

Introduction

The Amazon exhibits all the principle features associated with aquatic species richness globally (Albert and Reis 2011). It is the greatest interconnected fluvial system on the planet, extending over more than 7 million km. For 6 km downstream the two types of water run in parallel without mixing This phenomenon, called the Meeting of Waters, is due to differences in temperature, speed and water density. The water in the river Negro is acidic, with pH around 4.5, whereas the river Solimoes water is neutral, around pH = 7. Each tributary carries different aquatic flora and fauna adapted to its particular conditions, and the joining point, as other friction or contact zones, exhibits special

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Results

Conclusion