Common Name
KANAB AMBERSNAIL

Scientific Name
OXYLOMA KANABENSE

View Utah Distribution Map

Photo by Roy Averill-Murray
Photo Courtesy of Arizona Game and Fish Department

Utah Taxonomy

Ferriss (1910) was the first to collect this gastropod, in Utah in 1909, which he identified as Succinea hawkinsi; Pilsbry (1948), however, noted: "This form was referred to S. hawkinsi, with some doubt, at the time it was found ...." Chamberlin and Jones (1929) also included this population within Succinea hawkinsi, which they called Hawkins' swamp snail. (It should be noted that Chamberlin and Jones [1929] did include in the Utah fauna what they called Succinea haydeni, Hayden's swamp snail, for which they listed about 15 Utah localities extending in a band from Sevier County north through Sanpete, Utah, Salt Lake, and Weber counties to Cache and Rich counties.)

Pilsbry (1948) described the population discovered by Ferriss (1910) as a new subspecies, Oxyloma haydeni kanabensis. Clarke (1991) stated: "It [Oxyloma haydeni kanabensis] may deserve specific status." Spamer and Bogan (1993) reconsidered the taxon morphologically and suggested that it deserves specific rank. Wu (in England 1995) also has suggested that the taxon merits full specific status. Turgeon et al. (1988, 1998) and Groombridge (1993) have listed this taxon as a full species, Oxyloma kanabense.

Pilsbry (1948) designated the type locality as "'The Greens,' six miles above [i.e., north of] Kanab, on Kanab Wash", Kane County, Utah, where J. H. Ferriss collected the type and paratypes (no. 103166 in the collection of the Academy of Natural Sciences of Philadelphia) in 1909.

Recently Miller et al. (1997), using genetic techniques, have compared populations assigned to Oxyloma haydeni kanabensis from Three Lakes (Utah) and Vasey's Paradise (Arizona) with other populations assigned to Oxyloma haydeni haydeni from 2 localities in northern Arizona, Indian Gardens and -9 Mile Spring. They found that the Three Lakes population is closely related to the Indian Gardens population and recommended that the Indian Gardens population be removed from Oxyloma haydeni haydeni and assigned to the subspecies Oxyloma haydeni kanabensis. These authors noted the need for further work, particularly work using mt-DNA sequence data, and they also considered the suggestions of others that kanabensis may deserve full species status.

Status in Utah

This taxon has been reported from 2 localities in Utah, both in extreme southern Kane County (Clarke 1991, England 1995): the larger population, reported to be extant, is located at Three Lakes, about 10 km (6 mi) WNW of Kanab; a much smaller population, reported as seemingly extirpated, occurred in Kanab Creek Canyon, about 10 km (6 mi) N of Kanab. These 2 populations are about 2.1 km (1.3 mi) apart.

Clarke (1991) reported that considerably fewer than 85,000 individuals remain at the one Utah locality with an area much less than 2,000 acres (see Clarke 1991). At the only other reported Utah locality, which is much smaller, probably much less than 1 acre, Clarke found only 3 individuals in 1990 (Clarke 1991); England (1995) wrote that none has been found there since 1990, and the population has been presumed to be extirpated.

However, recent, on-going work by Vicky Meretsky (Indiana University) and co-workers (unpublished) has revealed a more extensive distribution and greater abundance of this taxon in the vicinity of Kanab than other recent reports (Clarke 1991, England 1995) had indicated, and they are investigating other parts of Kane County as well.

The main threats to this taxon in Utah are habitat loss through development and habitat degradation (dewatering of the habitat through water diversion) as well as direct destruction of the snails through trampling by livestock (Clarke 1991).

The population trend of this taxon in Utah, based on available reports (Clarke 1991, England 1995) appears to be one of precipitous decline. In June 1990 the Three lakes population was estimated by Clarke (1991) to contain about 100,000 individuals, but later, in September of that year, the population was considered by Clarke (1991) to have been considerably reduced by trampling by livestock, seemingly having lost about 15,000 individuals, and early in 1991 Clarke noted further disturbance (bulldozing), which he speculated was devastating even more of the population (Clarke 1991). The smaller population reportedly may be extirpated; Clarke (1991) found only 3 individuals there in 1990, and "[n]o individuals have been collected or observed since 1990" (England 1995).

Inventory is needed to ascertain the status (current size and extent) of the Three Lakes population and to re-examine the belief that the Kanab Creek Canyon population no longer exists. Prospective searches should be made elsewhere in southern Utah, especially in southern Kane County (e.g., along tributaries to the Colorado River system, especially tributaries to Lake Powell). (Again, Vicky Meretsky and co-workers are currently conducting such investigations.)

Habitats Utilized in Utah

Pilsbry (1948), in the type description of this taxon, noted that it was found "on a wet ledge among rocks and cypripediums." Clarke (1991) reported the habitat of the Three Lakes population as a marsh dominated by Typha in its wettest portion. Grasses, Carex, violets, plantains, and alders were also present. The densest snail aggregations were found under fallen Typha stalks, at the edges of thick Typha stands. The snails were also frequently observed just within the mouths of vole burrows. The presence of standing water appeared to be important to their local distribution. Clarke (1991) found that the habitat of the small population that existed along Kanab Creek also included Mimulus guttatus, Dodocatheon pauciflorum, Aquilegia micrantha, a tall grass species, and Juncus.

Sources:

  • Text modified from: Oliver, George V. and William R. Bosworth III. 1999. Rare, imperiled, and recently extinct or extirpated mollusks of Utah[:] a literature review. Publication number 99-29. Utah Division of Wildlife Resources, Salt Lake City. 230 pp.

  •