Description and Natural History Sample Clauses

Description and Natural History. ‌ Talussnails of the genus Sonorella are members of the family Helminthoglyptidae (Phylum Mollusca; Class Gastropoda, Subclass Pulmonata). Members of the genus are very similar, and distinguishing species from one another by casually examining shells in the field is difficult, if not impossible. Non-experts may even confuse members of the genus Sonorella with closely related genera including Eremarionta, Mohavelix, or Helminthoglypta (Bequaert and Xxxxxx 1973). Positive identification requires examination of reproductive organs by technical experts or genetic confirmation in the laboratory (Fairbanks and Xxxxxx 1980; Xxxxxx et al. 2010). The distribution and diversity of talussnails across the arid southwest are largely products of significant dispersal and vicariance that occurred during the numerous climatic changes of the Pleistocene era (Bequaert and Xxxxxx 1973; XxXxxx 1995). These conditions led to profuse speciation and substantial endemism amongst Sonorella. For instance, the Santa Xxxx and Patagonia mountains together contain four endemic talussnails (Bequaert and Xxxxxx 1973). Importantly, the conditions of the present-day arid Southwest render dispersal into new territories by Sonorella improbable (Bequaert and Xxxxxx 1973), including those occurring in the Pinaleño Mountains. In the Pinaleño Mountains, talussnails, depending on species, occur from about 1,890 to 2,800 m (6,200 to 9,186 ft) above mean sea level. This puts them in Madrean pine-oak woodlands, ponderosa pine forests, mixed evergreen conifer forests, and subalpine (spruce/fir) forests. They are not expected in montane xxxxxxx, or lower elevational vegetation communities, including desert, semidesert grassland, or Madrean encinal woodlands (except in more mesic, riparian stringers). Unfortunately, most of the published literature discusses the taxonomy and distribution of Sonorella, rather than details on their population status, microhabitat associations, and natural history traits. Because most species are known to inhabit talus slopes, and the fact that they are called talussnails may lead to an overly simplistic view of their habitat associations. Talus, or scree, is defined as rock fragments that break off from the cliffs above on fairly steep mountain slopes and aggregate in unstable piles (natural rockslides). However, this does not completely describe occupied habitat of Sonorella in the Pinaleño Mountains. For example, Wet Canyon, which is occupied by at least two Sonorella ...

Description and Natural History. ‌ The Huachuca springsnail is a moderate to large-sized snail with a shell height of 0.07 to 0.13 inches (1.7 to 3.2 millimeters) (Hershler and Landye 1988). The shell is moderately convex with slightly shouldered whorls. The inner lip of the shell is thin. The shell aperture is fused to or separate from body whorl. The umbilicus (a depression at the center of the shell whorls) is chink- like or open (USFWS 2014). a. Sylvania Spring or Scotia Canyon Spring), and Monkey Spring, in Santa Xxxx and Cochise Counties, Arizona. Landye (1981) treated populations from Canelo Hills Cienega, Monkey Spring, and Xxxxxx Spring as three separate Fontelicella species. These populations were synonymized (categorized as the same species) and the species was fully described by Hershler and Landye (1988) as Pyrgulopsis thompsoni from specimens examined from Cottonwood Spring, Monkey Spring, Canelo Hills Cienega, Xxxxxx Spring, and Xxxxxxxx Ranch Spring, Santa Xxxx County, Arizona; and from Ojo Caliente, Sonora, Mexico. USFWS carefully reviewed the available taxonomic information and concluded that P. thompsoni is a valid taxon (USFWS 2004). Importantly, relatively recent taxonomic research indicates significant genetic divergence within this species, with four evolutionarily significant units (ESUs) identified among nine populations examined (Hurt and Xxxxxxx 2004; Hurt 2004). Two ESUs comprise populations on the east and west slopes of the Huachuca Mountains, while two ESUs are represented by Cottonwood Spring and Monkey Spring (Hurt and Xxxxxxx 2004). Populations at lower elevations along Sonoita Creek and in the San Xxxxxx Valley possess all unique alleles with large genetic distances from other conspecific haplotypes, while the Monkey Spring population is both genetically and environmentally unique (Hurt 2004). At minimum this information seems to suggest taxonomic uncertainty within the larger complex referred to as Huachuca springsnail, and possibly taxonomic differentiation. No further work has been done regarding the taxonomy of the Huachuca springsnail populations, and until further information is received we consider all currently identified sites to be Huachuca springsnail (USFWS 2014). In the arid Southwest, snails of the family Hydrobiidae are largely relicts of the wetter Pleistocene Age (1.6 million 10,000 years ago) and are typically distributed across the landscape as geographically isolated populations exhibiting a high degree of endemism (found only in a pa...