Microevolution of the noble crayfish (Astacus astacus) in the Southern Balkan Peninsula

Abstract

BackgroundThe noble crayfish (Astacus astacus) displays a complex historical and contemporary genetic status in Europe. The species divergence has been shaped by geological events (i.e. Pleistocene glaciations) and humanly induced impacts (i.e. translocations, pollution, etc.) on its populations due to species commercial value and its niche degradation. Until now, limited genetic information has been procured for the Balkan area and especially for the southernmost distribution of this species (i.e. Greece). It is well known that the rich habitat diversity of the Balkan Peninsula offers suitable conditions for genetically diversified populations. Thus, the present manuscript revisits the phylogenetic relationships of the noble crayfish in Europe and identifies the genetic make-up and the biogeographical patterns of the species in its southern range limit.ResultsMitochondrial markers (i.e. COI and 16S) were used in order to elucidate the genetic structure and diversity of the noble crayfish in Europe. Two of the six European haplotypic lineages, were found exclusively in Greece. These two lineages exhibited greater haplotypic richness when compared with the rest four (of “Central European” origin) while they showed high genetic diversity. Divergence time analysis identified that the majority of this divergence was captured through Pleistocene, suggesting a southern glacial refugium (Greece, southern Balkans). Furthermore, six microsatellite markers were used in order to define the factors affecting the genetic structure and demographic history of the species in Greece. The population structure analysis revealed six to nine genetic clusters and eight putative genetic barriers. Evidence of bottleneck effects in the last ~5000 years (due to climatic and geological events and human activities) is also afforded. Findings from several other research fields (e.g. life sciences, geology or even archaeology) have been utilized to perceive the genetic make-up of the noble crayfish.ConclusionsThe southernmost part of Balkans has played a major role as a glacial refugium for A. astacus. Such refugia have served as centres of expansion to northern regions. Recent history of the noble crayfish in southern Balkans reveals the influence of environmental (climate, geology and/or topology) and anthropogenic factors.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-017-0971-6) contains supplementary material, which is available to authorized users.

Freshwater crayfish distribution update and maps for Greece: combining literature and citizen-science data

“…Published data relating to this species (mentioned as A. astacus balcanicus) for this particular ecosystem date back to the 1970s' (Koukoura, 1973). It has been recently confirmed by sampling (Laggis et al, 2017). Moreover, an interesting information, but ignored by the literature for presence of the species (also mentioned as A. a. balcanicus) in the springs of Arapitsa river (Vermio mountain), tributary of Aliakmonas river (3 km SW of the city of Naousa) was detected in the work of Koukoura (1973) (Fig.…”

“…The same Environmental Group proceeded to capturing of unspecified crayfish (some individuals with attached hatchlings) from the nearby village of Karya (located at the southern part of Olympos mountain) and released them in an enclosure in the springs of Mati brook, which feeds the lake. This is a case of unofficial restocking of A. astacus, as the species was recently identified by sampling in the source site (Laggis et al, 2017).…”

“…2, point 61). On the other hand, in a recent work by Laggis et al (2017), the origin of the founder populations in Doxa lake is stated as unknown. Therefore, the presence of the species in the water courses prior to damming cannot be ruled out.…”

“…Therefore, the presence of the species in the water courses prior to damming cannot be ruled out. In contrary, the population in Tsivlou lake was translocated from an unknown location and these two populations represent genetically different and distinct genetic clusters separated by genetic barriers (Laggis et al, 2017).…”

“…2, point 44). According to Laggis et al (2017), this population was translocated from Krania (borderline of Regions Western Macedonia and Epirus) during the last 10-15 years.…”