Origin, diversification and conservation status of talus snails in the Pinaleño Mountains: a conservation biogeographic study

Abstract

For many taxa, determining conservation status and priority is impeded by lack of adequate taxonomic and range data. For these problematic groups, we propose combining molecular techniques with careful geographic sampling to evaluate the validity, extent and phylogenetic relatedness of the proposed units of diversity. We employed such a strategy to document monophyletic lineages, range extents and phylogenetic relatedness for talus snails (genus Sonorella) in the Pinale˜no Mountains of Arizona, an isolated range that has the most vertical relief of any of the sky islands in Arizona. Three of the four species found in the Pinale˜no Mountains have been considered candidate species for protection under the Endangered Species Act. Further, one of these taxa, Sonorella macrophallus, is of particular concern and was protected under an USFS conservation agreement until 2004, due to its presumed endemicity to a narrow portion of one canyon. We collected a large dataset of 12S and COI mitochondrial DNA, and subsamples of reproductive morphology from specimens collected throughout the Pinale˜nos and from adjacent ranges (e.g. the Huachucas, Chiricahuas and Santa Catalinas). We generated a phylogeny based on the mitochondrial data, and matched clades with named species utilizing reproductive morphology. Our results show that both S. macrophallus and Sonorella imitator are relatively widespread across the Pinale˜nos while Sonorella grahamensis and Sonorella christenseni are restricted to very small areas. These results dramatically change our previous knowledge about range extents, especially for S. macrophallus. Given these results, land managers may need to reassess the status of all four Sonorella species. Finally, all Sonorella species from the Pinale˜nos are more closely related to each other than to other taxa on other ranges. This result strongly suggests that diversification of the four Sonorella species in the Pinale˜nos occurred in situ.

Climate change, extinction, and Sky Island biogeography in a montane lizard

“…The distribution of S. jarrovii is representative of many other species that are also confined to two or more Madrean Sky Island ranges (within the region), including other lizards ( Elgaria kingii, Sceloporus slevini, Sceloporus virgatus, and Plestiodon callicephalus ) and snakes ( Crotalus pricei, Crotalus lepidus, Crotalus willardi, Lampropeltis pyromelana, Senticolis triaspis, Tantilla yaquia; Brennan & Holycross, ). Similar distribution patterns are known in many other taxa, including birds (e.g., McCormack, Bowen, & Smith, ; Manthey & Moyle, ), amphibians (Barber, ; Streicher et al, ), snails (Weaver, Weaver, & Guralnick, ), insects (Downie, ; Dyer & Jaenicke, ; Smith & Farrell, ; Ober, Matthews, Ferrieri, & Kuhn, ), spiders (Masta, ), and plants (e.g., Moreno‐Letelier & Pinero, ; Perez‐Alquicira et al, ).…”