Testing freshwater Lago Mare dispersal theory on the phylogeny relationships of iberian cyprinid genera &lt;i&gt;Chondrostoma&lt;/i&gt; and &lt;i&gt;Squalius&lt;/i&gt; (Cypriniformes, Cyprinidae)

Ignacio Doadrio,José Ambrosio Carmona

doi:10.3989/graellsia.2003.v59.i2-3.260

Abstract

A phylogeny of the species in the genera Chondrostoma and Squalius was constructed based on the complete mitochondrial cytochrome b gene (1140pb). The molecular phylogeny was used to test the effect of the Mediterranean Lago Mare dispersal theory on the processes of divergence and speciation of European freshwater fishes. Phylogenetic relationships among Squalius samples and the molecular clock revealed that the ancestor of the current Iberian Squalius species inhabited a wide geographic area in the central and southwestern part of the former Iberian Peninsula during the Miocene before the Lago Mare phase. Similarly, the four main Iberian lineages of the genus Chondrostoma originated in the Middle-Upper Miocene. Hence, the Lago Mare phase of the Mediterranean Sea seems to have been a too recent paleogeographic event to have had any major impact on the dispersion of Squalius and Chondrostoma species. However, the reduction of the water-bodies during the Tortonian and Messinian may have intensified the isolation of populations. The Operational Biogeographic Units recovered from the Squalius and Chondrostoma phylogenies also reject the Lago Mare dispersal theory and support the idea that the differentiation processes were due to both the formation of the current hydrographical basin during the Plio-Pleistocene as well as to an earlier endorrheism event that occurred prior to hydrographical configuration.

Highlights

Primary freshwater fishes intolerant to marine conditions (Myers, 1938) have been of interest to biogeographers because of their dispersal ability, which is mainly restricted to freshwater contacts among different basins, lakes or rivers
The genus Chondrostoma comprises of approximately 30 species of freshwater fishes that are distributed throughout Europe and Asia; extending from the Iberian Peninsula to the Ural Mountains, and in the Middle East, from the Anatolian Peninsula to Iran
Using the relative-rate test (Robinson et al, 1998), we investigated whether the eight well-separated lineages, (“S. aradensis”, “S. torgalensis”, “S. carolitertii”, “S. pyrenaicus”, “Euro-Asiatic lineage”, ”Paratethys lineage” and “Italian and Balkanic species of the Mediterranean lineage”), had different substitution rates

Summary

Introduction

Primary freshwater fishes intolerant to marine conditions (Myers, 1938) have been of interest to biogeographers because of their dispersal ability, which is mainly restricted to freshwater contacts among different basins, lakes or rivers. It is commonly accepted that current geographical distribution of primary freshwater fishes is determined by a summary of historical changes related to the geological evolution of the region (Lundberg, 1993). Cyprinids with more than 1,700 species, display a high degree of diversity. Their wide biological and ecological plasticity gives this group an important role in biogeographical theories (Zardoya & Doadrio, 1998, 1999; Durand et al, 2003). Most theories regarding the paleobiogeography of European cyprinid fishes tried to explain which were the centre of origin and their dispersion routes (Banarescu & Coad, 1991), and only few were interested to know the barriers that explain the vicariant patterns observed in some cyprinid fishes (Howes, 1980, 1991; Doadrio, 1990, 1994)

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Results

Conclusion