Native <i>Dreissena</i> freshwater mussels in the Balkans: in and out of ancient lakes

Abstract

Abstract. The Balkans is a biogeographically highly diverse region and a worldwide hotspot of endemic freshwater diversity. A substantial part of this diversity is attributed to well recognized and potential ancient lakes in its southwestern part. However, despite considerable research efforts, faunal relationships among those lakes are not well understood. Therefore, genetic information from native representatives of the mussel genus Dreissena is here used to test the biogeographical zonation of the southwestern Balkans, to relate demographic changes to environmental changes, to assess the degree of eco-insularity, to reconstruct their evolutionary history, and to explore the potential of native taxa for becoming invasive.Phylogeographical and population genetic analyses indicate that most studied populations belong to two native species: D. presbensis (including the distinct genetic subgroup from Lake Ohrid, "D. stankovici") and D. blanci. In addition, the first confirmed record of invasive D. polymorpha in the southwestern Balkan is presented.The distribution of native Dreissena spp. generally coincides with the biogeographical zonations previously suggested based on fish data. However, there is disagreement on the assignment of the ancient lakes in the area to respective biogeographical regions. The data for Lake Ohrid are not conclusive. A closer biogeographical connection to lakes of the Vardar region and possibly the northern Ionian region is, however, suggested for Lake Prespa.The reconstruction of the evolutionary history of Dreissena spp. suggests that populations underwent demographic and spatial expansions in the recent past. Expansions

Testing the spatial and temporal framework of speciation in an ancient lake species flock: the leech genus <i>Dina</i> (Hirudinea: Erpobdellidae) in Lake Ohrid

“…Such distinctness has been suggested before based on biogeographical and phylogenetical studies in diverse taxa (e.g. Hauswald et al, 2008;Schultheiß et al, 2008;Wilke et al, 2010).…”

“…Finally, we calculated 95% confidence intervals for our time estimates including both the error of the phylogenetic analyses (in terms of branch-length variation of individual trees) and the error of the clock rate (see above) by utilizing a propagation of uncertainty approach (for details see Wilke et al, 2009Wilke et al, , 2010.…”

Distinct lake level lowstand in Lake Prespa (SE Europe) at the time of the 74 (75) ka Toba eruption

“…Published data from Lake Prespa indicate that the sedimentary record is very sensitive to environmental change over the last 92 ka, which is partly due to a relatively small volume (3.6 km 3 ), a large surface area (254 km 2 ), and a mean water depth of only ca. 14 m (Wilke et al, 2010;Damaschke et al, 2013;Wagner et al, 2012;Leng et al, 2013;Panagiotopoulos et al, 2013b). However, none of the published studies have considered that the sedimentary record could indicate the impact of the 74 (75) ka Toba eruption.…”

“…A potential recovery from the 74 ka lake level lowstand is probably correlated with an important spatial expansion event of D. presbensis from Lake Prespa to neighbouring water bodies. According to independent mitochondrial DNA data, this event took place about 72 ka ago, and the confidence interval for this estimate is very high (95 % CI: 0-153 ka; Wilke et al, 2010).…”

A freshwater biodiversity hotspot under pressure – assessing threats and identifying conservation needs for ancient Lake Ohrid

“…It is, however, obvious that highly impacted littoral parts such as the Ohrid Bay or areas near the Lin Peninsula have lately become home to several non-indigenous gastropod species (Albrecht et al, 2010 1 ). The number of observations of nonindigenous species will probably rise in the coming years and such species should be carefully monitored (e.g., Wilke et al, 2010).…”