Population genetics of the carinate pillsnail, Euchemotrema hubrichti: genetic structure on a small spatial scale

Abstract

Euchemotrema hubrichti (Pilsbry, 1940) is a polygyrid land snail known only from the Larue Pine Hills region of southwestern Illinois, USA. Despite the restricted range of the species, observations in the field suggested that patterns of genetic variation within E. hubrichti might show geographic structure. To assess the dispersal potential of E. hubrichti, a mark-recapture experiment was performed at two sites <100 meters apart. To evaluate the geographic distribution of genetic variation, a region of the mitochondrial cytochrome c oxidase subunit I gene was sequenced from 53 snails collected from sites spanning the species range. Markrecapture experiments suggested that population sizes at two sites were low and migration between sites was not detected. AMOVA and nested clade analysis (NCA) revealed significant genetic structure among sites. Two sites in particular appeared to be isolated from the others based on nested clade analysis. AMOVA also detected significant genetic differentiation among sites, but partitioning the data into two groups (populations 1 and 2) based on the NCA results did not explain a significant amount of genetic variation. Coalescent methods suggested that population sizes and migration rates for populations 1 and 2 are unequal. These patterns are likely due to the low dispersal ability of E. hubrichti and patchiness of preferred E. hubrichti habitat rather than an ancient vicariant event. These preliminary findings have implications both for the conservation of this species and for the population genetics of any spatially restricted endemic species with low dispersal ability.

Genetic variation within and between populations of hermaphroditic Bulinus truncatus tetraploid freshwater snails of the Albertine Rift, East Africa

“…The combinations of these factors amplify interpopulation divergence while minimizing intrapopulation variation. For example, using mark-recapture methods no dispersal was detected between two populations of the Carinate Pillsnail, Euchemotrema hubrichti separated by \100 m over a period of three years (Anderson, 2007). Such limited dispersal enables unique allele mutations to accumulate rapidly in each population thereby resulting in rapid genetic divergence between isolated populations.…”

High population differentiation in the rock-dwelling land snail (Trochulus caelatus) endemic to the Swiss Jura Mountains

“…Several studies have focused on the micro-scaled structure of land snail populations (Schilthuizen and Lombaerts 1994;Anderson 2007;Armbruster et al 2007a). Trochulus caelatus (formerly Trichia caelata) is a small terrestrial gastropod (shell height: 4 mm, width: 8 mm; Kerney et al 1983) endemic to the northwestern Swiss Jura Mountains.…”

Population structure and demographic inferences concerning the endangered onychophoran species Epiperipatus acacioi (Onychophora: Peripatidae)

“…The analyses of nucleotide and haplotype diversity revealed that populations of E. acacioi present higher levels of genetic diversity when compared with populations of other invertebrate endangered species (Moya et al, 2004;Anderson, 2007;Strasser and Barber, 2009). Due to the lack of data about mutation rates (μ) for the COI gene in Onychophora, the population sizes could not be estimated.…”

“…Another factor influencing gene flow within and among animal populations is vagility. Species with low vagility are expected to have low levels of gene flow and high levels of population differentiation, and they are more sensitive to habitat loss or degradation (Bohonak, 1999;Anderson, 2007).…”