Ancient divisions, recent expansions: phylogeography and population genetics of the round goby Apollonia melanostoma

Abstract

During the past two decades, the round goby Apollonia melanostoma (=Neogobius melanostomus) has expanded its range via shipping transport and canals, extending north and west from the Ponto-Caspian region of Eurasia and to the North American Great Lakes. Exotic populations of the round goby have been very successful in the Baltic Sea and the Great Lakes regions, exerting significant ecological changes. Our study evaluates the population genetic and biogeographical structure of the round goby across its native and nonindigenous ranges, in light of geological history and its expansion pathways. We analyzed seven new nuclear microsatellite loci and mitochondrial DNA cytochrome b gene sequences from 432 individuals in 22 locations. Population structure was tested using F(ST)-analogs, phylogenetic trees, clustering diagrams, Bayesian assignment tests and nested clade analyses. Results show that native populations in the Black vs. the Caspian Sea basins diverge by 1.4% and c. 350,000 years, corresponding to closure of their prior connections and supporting the taxonomic separation of the Black Sea A. m. melanostoma from the Caspian Sea A. m. affinis. Their within-basin populations diverge by approximately 0.4% and 100,000 years. Nonindigenous populations in the Baltic Sea and Danube and Dnieper Rivers trace to separate northern Black Sea origins, whereas the upper Volga River system houses mixed populations of A. m. melanostoma and A. m. affinis. Native populations average twice the genetic diversity of most exotic sites; however, sites in the Volga River system have high diversity due to mixing of the two taxa. Our results highlight how vicariance and anthropogenic disturbances have shaped a rapidly expanding species' genetic heritage.

Different life-histories of native and invasiveNeogobius melanostomusand the possible role of phenotypic plasticity in the species’ invasion success

“…Thus, being aware that the data tested had some limitations typical for field studies, all the three quantitative parameters of life-history traits examined in this study have supported the theory of alternative ontogenies and invasive potential. Due to a pronounced founder / bottleneck effect in the population of N. melanostomus from Slovakia, the genetic diversity (allele frequencies) in this invasive population was found to be strongly limited compared to native populations (Brown and Stepien, 2008). Therefore, variations in the life-history described in non-native N. melanostomus from the Danube appear to be a demonstration of the species' phenotypic plasticity.…”

Population genetic history of the dreissenid mussel invasions: expansion patterns across North America

“…Another possible evolutionary outcome for an introduction is no significant change in genetic diversity between the native and introduced ranges. This is possible if large population size is maintained during an invasion (Brown and Marshall 1981) or regained shortly following introductions (Zenger et al 2003).…”

Upstream expansion of round goby (Neogobius Melanostomus) – first record in the upper reaches of the Elbe river

“…However, with much current research activity in aquatic invasions the possible source of this invasion can probably be indicated soon. Future ecological studies of round goby, supplemented by recent papers discussing its European phylogeography (Brown and Stepien, 2008;Mombaerts et al, 2014), are required to estimate real migration abilities of this species and the role of humans in its spread. …”