Molecular Ecology (2010) 19, 4708–4722 doi: 10.1111/j.1365-294X.2010.04844.x
Range-wide population genetic structure of the European bitterling (Rhodeus amarus) based on microsatellite and mitochondrial DNA analysis
J. BRYJA,*– C. SMITH,† A. KONECˇ NY´ * and M. REICHARD*† *Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Kveˇtna´ 8, 603 65 Brno, Czech Republic, †School of Biology, University of St Andrews, St Andrews, Fife KY16 8LB, UK
Abstract An understanding of recent evolutionary processes is essential for the successful conservation and management of contemporary populations, especially where they concern the introduction or invasion of species outside their natural range. However, the potentially negative implications of intraspecific introductions and invasions have attracted less attention, although they also represent a potential threat to biodiversity, and are commonly facilitated through human activities. The European bitterling (Rhodeus amarus) is a small cyprinid fish that decreased greatly in its distribution during the 1970s and 1980s and was subsequently included on many European conservation lists. This decline appears to have reversed, and the extent of its distribution now exceeds its former range. We used a combination of 12 microsatellite markers and cytochrome b sequences on a large data set (693 individuals) across the current range of the European bitterling to investigate possible scenarios for its colonization of Europe. We show that the inferred history of colonization of Europe was largely congruent between mitochondrial and nuclear markers. The most divergent mtDNA lineages occur in the Aegean region but probably are not reproductively isolated as the Aegean populations also displayed mtDNA haplotypes from other lineages and nuclear data indicated their close relationship to Danubian populations. Much of Europe is currently populated by descendants of two main lineages that came to natural secondary contact in western Europe. An approximate Bayesian computation analysis indicates different dates for admixture events among western and central European populations ranging from the last deglaciation (natural) to the last few centuries (human- assisted translocations).
Keywords: co-evolution, conservation, fish, intraspecific introduction, non-native populations Received 16 November 2009; revision received 19 August 2010; accepted 25 August 2010
have been considered invasive and subject to eradica- Introduction tion programmes have later been discovered to be The distinction between native and non-native popula- native to a region (van Leeuwen et al. 2008). Likewise, tions is often problematic at the interspecific level (i.e. some species considered to be indigenous, and sub- non-native species introductions). Some species that jected to legal protection and conservation efforts, have later proven to be recent colonizers via human-assisted Correspondence: Dr Josef Bryja, Fax: +420 568423121; dispersal or translocations (Castilla et al. 2002). Within E-mail: [email protected] – Present address: Department of Population Biology, Institute species, it is even more challenging to identify native of Vertebrate Biology, Academy of Sciences of the Czech and non-native populations and delineate their natural Republic, Studenec 122, 675 02 Koneˇsˇ´ın, Czech Republic. distributions. Populations from certain regions may be