Phylogeography and RAPD-PCR variation in Hoplias malabaricus (Bloch, 1794) (Pisces, Teleostei) in southeastern Brazil

Jorge A Dergam,Carlos E Schaeffer,Alexandre L Godinho,Samuel R Paiva,Fabio Vieira

doi:10.1590/s1415-47572002000400005

Abstract

In the Rio Doce basin of southeastern Brazil, the freshwater fish Hoplias malabaricus (trahira) is a widespread predatory characin and one of the few resilient native fishes in a highly impacted lake system. In order to test for genetic differentiation in populations within this basin and for biogeographic relationships among populations of this species in other basins, a study was conducted using RAPD-PCR analysis of Rio Doce samples (N = 63) and phylogeographic analyses with mitochondrial DNA (mtDNA) haplotypes, including the Rio Grande and Macacu river basins. In the Rio Doce basin, the patterns of genetic similarity of RAPD-PCR markers (individual fingerprinting and Nei’s genetic distance) suggest the existence of two genetically different groups, one composed of the lacustrine populations Carioca and Dom Helvécio, and the other of riverine and the remaining lacustrine populations. The differences in the RAPD-PCR patterns may be explained by the existence of sub-basins within this lacustrine system. A maximum parsimony tree of cytochrome b fragment (383 base pairs) supports the view that trahiras of the Rio Doce share a complex biogeographic history with those of neighboring basins. The phylogeographic patterns may be explained by a common history of the watersheds of the Rio Doce, Paraíba do Sul, and Rio Grande basins, corroborating the hypothesis of a Plio-Pleistocene separation of these drainage systems, forming the Mantiqueira "divortium aquarium".

Highlights

The Rio Doce basin is one of the eastern river basins of the State of Minas Gerais, Brazil, with its headwaters located in the Serra do Espinhaço, within the Serra da Mantiqueira mountain system, flowing eastward to the Atlantic Ocean
The data support the view that, within the Rio Doce basin, RAPD-polymerase chain reaction (PCR) markers are sensitive to Quaternary events, and molecular similarity between the lacustrine populations Dom Helvécio (DH) and CR may indicate that these two lakes share a similar geological history, which is supported by their highly similar species composition (Sunaga and Verani, 1985)
Like other biochemical and molecular markers, techniques based on RAPD alleles do not necessarily involve the genomic regions responsible for adaptive traits which have been traditionally used for granting Evolutionary Significant Units (ESU) status to local populations or species (Allendorf, 1995)

Summary

Introduction

The Rio Doce basin is one of the eastern river basins of the State of Minas Gerais, Brazil, with its headwaters located in the Serra do Espinhaço, within the Serra da Mantiqueira mountain system, flowing eastward to the Atlantic Ocean. The Rio Doce basin is considered a unique river system, due to the occurrence of a complex system of Quaternary lakes in its mid-valley (Petri and Fúlfaro, 1983), formed during the last glaciation maxima, the first one between 14,000 to 10,000 years ago (ya) and thereafter, between 7,800 to 3,360 ya (Tundisi and De Meis, 1985). These lakes have been compared to “islands”, based on their low levels of similarity in terms of species composition (Sunaga and Verani, 1985). The age of the lacustrine system and the probable existence of different levels of isolation (Figure 1) in the basin, due to barriers such as prominent waterfalls and lakes, make this region a unique scenario for the study of the tempo and mode of evolution-

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Conclusion