Origin of Rhithropanopeus harrisii (Crustacea: Panopeidae) invasion on the Southwest Atlantic coast

Abstract

Exotic species can have large impacts on the communities and ecosystems where they are established. Understanding the invasion routes and the processes that allow the establishment of these exotic species is necessary to minimize their impacts. Genetic tools allow the comprehension of dispersion patterns, which is fundamental to forecasting the propagation of invasive species. The mud crab Rhithropanopeus harrisii is native to North America but has invaded different water bodies around the globe in the past century. To clarify the invasion routes and the population source of the mud crab in Lagoa dos Patos (Brazil), a partial region of CO1 was used and compared to sequences extracted from individuals from Europe and North America. The haplotype diversity found in Brazilian, European, and western North American samples was lower than that in the Gulf of Mexico and eastern North America (native areas). The genetic distances of the 11 analyzed populations were high (Phi-st > 0.8), and the shortest genetic distance was found between southern Brazil and North Carolina (eastern United States). Our results suggest that the population from North Carolina was the source of the Brazilian population, and the ballast water of ships that arrived at Rio Grande Port was likely the vector of this invasion.