Found, forgotten, and found again: systematics and distribution of Cooper’s Rocky Mountain snail (Oreohelix cooperi) on a sky island in the Canadian Prairies

The results of phylogeographic and biogeographic studies of organisms residing in isolated habitats provide key insights into processes of population differentiation, speciation, and endemicity. Several of the approximately 70 species of land snail in the genus Oreohelix Pilsbry, 1904 occur only on isolated sky islands on the North American Great Plains. The restricted distributions of these snails have led to concerns regarding their conservation status, particularly in western Canada where their systematics and distributions are poorly known. Cooper’s Rocky Mountain snail (Oreohelix cooperi (Binney, 1858)) has been reported from several sky islands in the northern United States. We evaluated morphological characteristics and sequence data for samples of putative O. cooperi collected from a sky island in the Cypress Hills area of southeastern Alberta and southwestern Saskatchewan. COI sequences matched O. cooperi from snails collected on sky islands in South Dakota and Wyoming and morphological analyses of shell shape and male genitalia were consistent with published descriptions of this species. COI and ITS2 sequences and morphological characteristics of these snails did not match other Oreohelix spp. found in the Cypress Hills and in the adjacent Rocky Mountains. Our results extend the distribution of O. cooperi into southern Canada and confirm its endemicity within sky islands of western North America.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Genetic compatibility between sexual and clonal genomes in local populations of the hybridogenetic Rana esculenta complex.

Hybridogenetic species possess a hybrid genome: half is clonally inherited (hemiclonal reproduction) while the other half is obrained each generation by sexual reproduction with a parental species. We addressed the question of whether different hemiclones of the hybridogenetic water frog Rana esculenta are locally adapted for genetic compatibility with its sexual parental host Rana lessonae. We artificially crossed R. esculenta females of three hemiclones (GUT1, GUT2, GUT3) from a pond near Gütighausen, Switzerland and one hemiclone (HEL1) from near Hellberg, Switzerland each to R. lessonae males from both populations. We also created primary hybrids by crossing the same R. lessonae males from both populations to R. ridibunda females from Poznan´, Poland (POZ). Tadpoles were then reared in the laboratory at two food levels to assess their performance related to early larval growth rate, body size at metamorphosis and length of the larval period. Tadpoles from hemiclones GUT1, GUT3 and POZ had higher growth rates than those from hemiclones GUT2 and HEL1 at the low food level, but at the high food level all growth rates were higher and diverged significantly between hemiclones GUT2 and HEL1. Tadpoles from the intrapopulational crosses GUT2 x GUT and HEL1 x HEL were larger at metamorphosis than those from the interpopulational crosses GUT2 x HEL and HEL1 x GUT. A high food level increased the size at metamorphosis in all tadpoles. A high food level also decreased the days to metamorphosis and tadpoles from GUT1, GUT3 and POZ had the shortest larval period whereas those from GUT2 and HEL1 had the longest. These results indicate that the differential compatibility of clonal genomes may play an important role in hybridogenetic species successfully using locally adapted sexual genomes of parental species and that interclonal selection is likely important in determining the distribution of hemiclones among local populations