The invasive bighead goby Ponticola kessleri displays large‐scale genetic similarities and small‐scale genetic differentiation in relation to shipping patterns

Abstract

Colonization events, range expansions and species invasions leave genetic signatures in the genomes of invasive organisms and produce intricate special patterns. Predictions have been made as to how those patterns arise, but only very rarely, genetic processes can be monitored in real time during range expansions. In an attempt to change that, we track a very recently established invasive population of a fish species, the bighead goby Ponticola kessleri, with high temporal and spatial resolution through 2 years to identify patterns over time. We then compare Swiss and German samples of bighead goby along the river Rhine using microsatellites, mitochondrial D-loop sequences and geometric morphometrics to investigate geographic patterns. We detect weak temporal and strong geographic patterns in the data, which are inconsistent with isolation by distance and indicate long range transport. In search of an explanation for our observations, we analyse the vector properties and travel patterns of commercial vessels on the river Rhine. We present evidence that freshwater cargo ships and tankers are plausible vectors for larvae of invasive goby species. We also present indications that cargo ships and tankers act as differential vectors for this species. In summary, we present genetic data at unique temporal resolution from a vertebrate invasion front and substantiate the paramount role of commercial shipping in freshwater fish translocations.

Genetic patterns across an invasion's history: a test of change versus stasis for the Eurasian round goby in North America

“…As in the round goby, exotic bighead goby Ponticola kessleri populations showed no significant genetic changes over two years post‐introduction in Switzerland, where they significantly diverged among different river systems (Adrian‐Kalchhauser et al . ). The bighead goby belongs to the same family (Gobiidae) and subfamily (Benthophilinae) as the round goby and shares a common native biogeographic history in the Ponto‐Caspian region (Neilson & Stepien ; Stepien & Neilson ).…”

Persistence of Resident and Transplanted Genotypes of the Undomesticated Yeast, Saccharomyces paradoxus in Forest Soil

“…A remarkable pattern of persistence of genotypes in their sites of origin was observed over this one-year time span. In the present study, we sampled these 72 sites again in 2016 and a limited selection of eight sites again in 2017 (Table 1), extending the sampling times of 2014 and 2015 reported by Xia et al (10) by two years.…”

“…In this study, we first followed naturally occurring genotypes of S. paradoxus over a three-year period on a fine geographical scale of marked sites in a natural woodland. This extended the time frame covered by our earlier study (10) by two years. This part of the study included only enrichment culturing and therefore registered only presence or absence, not abundance of yeasts.…”

“…Our initial goal was to identify naturally occurring genotypes of S. paradoxus and to track their distributions over time. The sampling area included the same sites studied via enrichment culture by Xia et al (10) in 2014 and 2015 and this study extended the earlier sampling into 2016 and 2017 (Table 1). The sample encompassed four oak trees, with three sites around the base of each tree separated by buttress roots, with six microsites in each site (Fig.…”

Colonizing Islands of water on dry land—on the passive dispersal of fish eggs by birds

“…We acknowledge that genetic work can greatly advance our understanding of colonization patterns in time and space. For example, genetic data can help to re‐construct colonization patterns if population genetics are on par with vector activity (Adrian‐Kalchhauser et al., ). Population genetics, however, cannot identify the nature of the propagule which was transported by the vector.…”