Listing
Nov 21, 1991
Nov 21, 1991 Listing
ETWP; Animal Candidate Review for Listing as Endangered or Threatened Species; 56 FR 58804 58836
- Publication type: CNOR
Item 1
FWS Focus
Overview
Characteristics
Overview
The rough hornsnail is a freshwater snail, endemic to the Coosa River system in Alabama.
Scientific Name
Pleurocera foremani
Common Name
Rough Hornsnail
FWS Category
Snails
Identification Numbers
Characteristics
Characteristic category
Habitat
Characteristics
Habitat
- Rough hornsnails are primarily found on gravel, cobble, bedrock, and mud in moderate currents. They have been collected at depths of 1 meter (3.3 feet) to 3 meters (9.8 feet).
- The species appears to be very tolerant of silt deposition.
Characteristic category
Physical Characteristics
Characteristics
Size & Shape
- The rough hornsnail’s shell is elongated, pyramidal, and thick.
- The shell can grow to 33 millimeters (1.3 inches) in length.
- The aperture is elongated, angular, and channeled at the base. The presence of a double row of prominent nodules or tubercles on the lower whorls above the aperture is the most distinctive feature that separates it from other hornsnails (Tyron 1873). These tubercles, along with the size and shape of the shell, distinguish the species from all other pleurocerid snails (Elimia species, Leptoxis species, Pleurocera species) in the Mobile River Basin.
Color & Pattern
- The shell has as many as nine yellowish-brown whorls.
- The aperture is usually white nacre.
Characteristic category
Life Cycle
Characteristics
Reproduction
- Snails in the genus Pleurocera generally lay their eggs in a spiral arrangement on smooth surfaces (Sides 2005), whereas Elimia snails generally lay eggs in short strings (P. Johnson pers. comm. 2006). Although some attempts to induce rough hornsnails to lay eggs in captivity have been unsuccessful (Sides 2005), others have observed females laying eggs individually or in short “strips” (3-10 eggs) during late April into July (Johnson in litt. 2009).
- Cultured rough hornsnails have become reproductively active in their second year (Johnson in litt. 2009).
Life Span
- Some adult individuals collected from the wild have survived in captivity for 3 years, suggesting a life span of 4 to 5 years in the wild (Garner in litt. 2009; Johnson in litt. 2009).
Geography
Characteristics
Range
- Historical Range
- Historical museum records of the rough hornsnail in the Coosa River (FLMNH in litt. 2006, and elsewhere) indicate that the species occurred in Etowah, St. Clair, Shelby, Talladega, and Elmore Counties, Alabama, an historical range of approximately 322 river kilometers (200 river miles).
- There are also historical museum records of this species from nine Coosa River tributaries in Alabama, including Big Wills Creek in Etowah County; Kelly, Big Canoe, and Beaver Creeks in St. Clair County; Ohatchee Creek, Calhoun County; Choccolocco and Peckerwood Creeks in Talladega County; Yellowleaf Creek, Shelby County; and Yellow Leaf Creek in Chilton County (FLMNH in litt. 2006).
- Current Range
- There are currently only five known populations of the rough hornsnail in Alabama: lower Yellowleaf Creek in Shelby County; lower Coosa River below Wetumpka Shoals in Elmore County; lower Weogufka Creek in Lay Lake; lower Walnut Creek in Chilton County; and lower Hatchet Creek in Coosa County.
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