Genetic Variation within Western Ambersnails (Oxyloma) with respect to the federally endangered Kanab Ambersnail (Oxyloma haydeni kanabense)

 
Collaborators:

• Dr. Melanie Culver, School of Natural Resources, University of Arizona
• Dr. Mark Miller, Utah State University
• Dr. Barry Roth, San Francisco
• Jeff Sorensen, Arizona Game and Fish

The land snail genus Oxyloma (Pulmonata: Succineidae) includes the federally endangered Kanab ambersnail (Oxyloma haydeni kanabense Pilsbry), which is currently known from only two locations in the United States (Three Lakes, Utah and Vaseys Paradise along the Colorado River in Grand Canyon National Park). Recently, the Kanab ambersnail received considerable attention because its presence at Vaseys Paradise has implications for the ecosystem-wide management of the Colorado River, mainly due to the fact that previous planned high-flow releases from Glen Canyon Dam destroyed or degraded approximately 10% of the Kanab ambersnail habitat at Vaseys Paradise. As a result of the habitat destruction at Vaseys Paradise, the U.S. Fish and Wildlife Service ruled that no further experimental high-discharge floods could be conducted until additional Kanab ambersnail populations were discovered or established. Because of this ruling, a situation existed where the management of a single endangered species stood in direct opposition to the management of an entire ecosystem.

Adding to the controversy surrounding Oxyloma and the Kanab ambersnail are recent anatomical and genetic analyses of the genus. These analyses demonstrated a lack of correspondence between genetic characteristics of specimens and their identifications based on traditional taxonomic criteria, thus raising questions about the validity of the taxonomy of Oxyloma and the protected status received by Kanab ambersnails.

We use four autosomal and two mitochondrial loci to study the population genetics and the phylogeography of Oxyloma populations in Arizona and Utah. We are particularly interested in dispersal patterns explaining the current distribution of the populations.

Photo courtesy of the Arizona Game and Fish Department