The Contact Zone of Phylogenetic Lineages of Freshwater Fish in Arctic Eurasia: Genetic Polymorphism of Coregonid Populations

Abstract

The reconstruction of regional fauna history is very important in the context of recent climate change and anthropogenic transformation. We analyzed the mitochondrial nd1 gene polymorphism in populations of whitefish Coregonus lavaretus and certain widespread Eurasian ciscoes species: vendace Coregonus albula and least cisco Coregonus sardinella, inhabiting waterbodies from the Anadyr River in the east (the Pacific Ocean basin) to Loch Lomond in the west (the Atlantic Ocean basin). Distinct phylogenetic lineages and secondary contact zones have been found in these species. Most of these are species-specific with the exception of the zone from the Pechora River basin to at least the western part of the Taymyr Peninsula, in which whitefish, vendace, and least cisco share with each other and with various cold-water hydrobionts. We associate differences in the geographical position and propagation of the secondary contact regions with the species-specific morpho-ecological features, in particular, with the ability for long-term migrations. Based on the data obtained, we also discuss certain limitations of the phylogeography and phylogeny of the considered coregonid species and the correctness of the taxonomic status of certain populations or their groups.

Comparison of the Efficiency of Single-Locus Species Delimitation Methods: A Case Study of a Single Lake Fish Population in Comparison against the Barcodes from International Databases

“…Most methods did not support a separation of several taxa within Esox lucius and Rutilus rutilus, in contrast to the opinions of some recent investigators [115,116]. Finally, within the genus Coregonus we observed low genetic differentiation [117] between traditionally separated [118] species, such as European (C. albula) and Siberian (C. sardinella) vendace. Only the Arctic cisco (C. autumnalis) represented a separate mOTU (Figure 2).…”

Trends of Eurasian Perch (Perca fluviatilis) mtDNA ATP6 Region Genetic Diversity within the Hydro-Systems of the Eastern Part of the Baltic Sea in the Anthropocene

“…Even though a large body of data concerning the distribution, abundance, and ecology of many fish species, both in freshwater and brackish environments [29,30], has been collected, the findings on their intraspecific genetic variability [22,[31][32][33], phylogeographic relationships [34][35][36], and postglacial history [24,37,38] remain fragmented. Furthermore, such data are quite limited even for extensively studied fish species [20,39].…”

“…Populations of contemporary aquatic fauna and flora in the Black and Baltic Sea Regions are thought to harbour unique natural diversity because of the Pleistocene [34]. However, during the last ice age, a major qualitative difference between these large territories appeared, as most of the Black Sea Region remained ice free while the Baltic Sea Region-especially its eastern part, including the current territories of Latvia, partially Lithuania, and Belaruswas covered in ice [39]. It is reasonable to use postglacial fish as model species [24] to investigate the trends of microevolutionary processes that occurred during and after the last ice age in the macrogeographic area encompassing these two unique regions.…”