Arizona’s Native Mollusks
Snails in the desert? Surprisingly, Arizona is home to over 220 native snails and one native freshwater mussel (the California floater). We also have another 21 non-native species of mollusks, including the troublesome quagga mussel and New Zealand mudsnails (both relatively recent invaders). With the exception of a few, very little is known about our native mollusks–mostly just their taxonomic identification, some point locality information, and generalized assumptions on their life history and threats to survival. Many species of native snails are apparently endemic to Arizona (found nowhere else) and occur in isolated springs, rock slides, or other undeveloped locations. It is believed that many of these local endemics were once more widely distributed across Arizona’s landscapes, but when the last ice age ended and the Southwest became more arid, these snail populations became early victims of climate change.
Under Arizona’s Title 17, the Department has management authority for crustaceans and mollusks in the state. The harvest and collection of crustaceans and mollusks is regulated under Commission Order 42 in the Arizona Fishing Regulations. The Department and its federal partners conduct monitoring surveys and management actions for several mollusks of concern across the state. One such species is the Kanab ambersnail — Arizona’s smallest endangered species. Several aquatic springsnails and terrestrial talussnails are candidate species under the federal Endangered Species Act. The Department has identified 27 species of mollusks as “Species of Greatest Conservation Need” in Arizona (tier 1a and 1b status), as they are listed below.
Nongame Mollusks Species
Species abstracts
- Anodonta californiensis, California Floater
- Discus shimekii cockerelli, Cockerell’s Striate Disc (Snail)
- Oreohelix grahamensis, Pinaleno Mountainsnail
- Oreohelix yavapai cummings, Yavapai Mountain Snail
- Oxyloma haydeni haydeni, Niobrara Ambersnail
- Oxyloma haydeni kanabensis, Kanab Ambersnail
- Pyrgulopsis arizonae, Bylas Springsnail
- Pyrgulopsis bacchus, Ground Wash Springsnail
- Pyrgulopsis bernardina, San Bernardino Springsnail
- Pyrgulopsis conica, Kingman Springsnail
- Pyrgulopsis deserta, Desert Springsnail
- Pyrgulopsis glandulosa, Verde Rim Springsnail
- Pyrgulopsis montezumensis, Montezuma Well Springsnail
- Pyrgulopsis morrisoni, Page Springsnail
- Pyrgulopsis simplex, Fossil Springsnail
- Pyrgulopsis sola, Brown Springsnail
- Pyrgulopsis thompsoni, Huachuca Springsnail
- Pyrgulopsis trivialis, Three Forks Springsnail
- Sonorella allynsmithi, Squaw Peak Tallussnail
- Sonorella christenseni, Clark Peak Talussnail
- Sonorella eremita, San Xavier Talussnail
- Sonorella grahamensis, Pinaleno Tallussnail
- Sonorella imitator, Mimic Tallussnail
- Sonorella macrophallus, Wet Canyon Talussnail
- Sonorella papagorum, Papago Talussnail
- Tryonia gilae, Gila Tryonia
- Tryonia quitobaquitae, Quitobaquito Tryonia
