Search

Water scorpions belonging to the genus Nepa are predatory freshwater aquatic insects of the order Hemiptera. There are currently five accepted species, with a Holarctic distribution: N. cinerea (Eurasia and Northern Africa), N. sardiniensis (Sardinia and Corsica), N. anophthalma (endemic to Movile Cave, Romania), N. apiculata (North America) and N. hoffmanni (Eastern Asia). Mitochondrial and nuclear genetic markers indicate a correlation between genetic diversity and geographic distribution. Analyses also reveal a cryptic diversity in the Western Mediterranean basin, with specimens of the cinerea clade being assigned to the sardiniensis clade. The cave-adapted N. anophthalma is genetically closest to N. cinerea, suggesting surface populations of N. cinerea as possible ancestors. N. cinerea samples from three cave systems in Italy indicate various degrees of gene flow between surface and subterranean populations and an instance of a possible incipient speciation event. Despite the overlap in distribution range in mainland Eastern Asia between N. cinerea and N. hoffmanni, there is a high genetic distance between the two species. A similar value of genetic distance is found between N. cinerea and N. apiculata, but also between N. hoffmanni and N. apiculata, suggesting the assignment of N. hoffmanni and N. apiculata to different genera. The single species currently considered as stygobiotic, N. anophthalma, deserves more research to understand the timing of colonization of Movile groundwater by its surface ancestors.

This work aimed to describe the genetic landscape of the Balkan Peninsula, as revealed by STR markers commonly used in forensics and spatial methods specifically developed for genetic data.We generated and analyzed 16 short tandem repeats (STRs) autosomal genotypes in 287 subjects from ten administrative/geographical regions of Eastern Europe (Romania and the Republic of Moldova). We report estimates of the allele frequencies in these sub-populations, their fixation indexes, and use these results to complement previous spatial analyses of Southern Europe.In seven out of ten analyzed regional samples the heterozygosity, averaged across loci, was lower than expected. The average Fis was 0.011. Among the 16 loci, five returned a significant fixation index Fst. The composite Fst across the 16 loci, among the 10 regional samples, was 0.00417, a figure twice as large as that obtained with the same markers across the entire Northern Mediterranean. The first spatial principal component (sPC1) returned the picture of a Central-European pattern of frequencies for the Carpathians, which extended to the Southern boundary of the Balkan Peninsula. However, the 8 alleles extracted by sPC1 returned a picture of a strong reduction of the migration rate in the Carpathian region, mostly between the inner locations.Our results revealed an unexpected heterogeneity in the area. We believe that populations from some regions will require treatment as distinct entities when considered in forensic applications.