Pyrgulopsis roswellensis

Roswell Springsnail

FWS Focus

Overview

Characteristics
Overview

The Roswell springsnail (Pyrgulopsis roswellensis) is an aquatic species in the Hydrobiidae family of mud snails. The genus Pyrgulopsis is one of the most abundant and varied types of aquatic life native to the American Southwest. The Roswell springsnail lives in wetland sinkhole and spring-fed habitat in caves and karsts, and was federally listed as endangered in 2005 due to its limited distribution, low mobility, fragmentation of habitat, and threats such as surface and groundwater contamination and depletion. 

Scientific Name

Pyrgulopsis roswellensis
Common Name
Roswell Springsnail
FWS Category
Snails
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Sound

Roswell springsnail sounds have not been identified or recorded.

Weight

No recorded weight measurements for Roswell springsnail are available at this time.

Size & Shape

The body of the Roswell springsnail is soft, with a muscular foot, a visceral mass, eyes, and tentacles that protrude from their head region. They live within cone-shaped shells made of calcium carbonate that become increasingly narrow towards the top. These shells have one valve that regulates the springsnail's air and fluid, and are formed by secretion from glands in their body wall. Shell lengths range from 3 to 3.5 millimeters (0.12 to 0.14 inches) long, and females are characteristically larger. 

Color & Pattern

The shells of Roswell springsnails are spiral-patterned, tan colored, and narrowly conical in shape. Roswell springsnails have an amber colored operculum with white spiral streaks. This is a diagnostic feature that can be used to distinguish the species from Koster’s springsnails (Juturnia kosteri), whose operculum has practically no color.

Characteristic category

Life Cycle

Characteristics
Life Span

Roswell springsnails have recorded lifespans ranging from 9 to 15 months. Most individuals live for less than one year, and females are longer-lived than males.  

Reproduction

Hydrobiid snails are sexually dimorphic and the male copulatory organ, known as a verge, projects from the neck area and does not retract. Resource abundance and productivity are regulating factors in other similar snail populations, where increased competition for limited food resources has reduced fertility and juvenile survival. Trematode (internal parasites) infestation and parasitic castration may also regulate reproduction and influence population size.

Life Cycle

Roswell springsnails breed seasonally from March through September. They are ovoviviparous, meaning they produce eggs that hatch in the body of the parent, usually the female. Population recruitment is continuous throughout the breeding season, because production of live young is serial rather than in broods. Individual snails may reproduce several times during the spring through fall. 

Characteristic category

Similar Species

Characteristics
Similar Species

The Roswell springsnail and Koster's springsnail have overlapping range and similar looking shells. Roswell springsnails can be distinguished from Koster’s springsnails by an amber colored operculum (a lid closing the opening of the shell when the snail is retracted) with white spiral streaks, while the operculum of Koster’s springsnail is nearly colorless. 

Characteristic category

Food

Characteristics
Food

Roswell springsnails find their food on underwater surfaces; their diet consists primarily of algae, bacteria, and fungi, and may also contain  dead organic, plant and animal material.

Characteristic category

Behavior

Characteristics
Behavior

Roswell springsnails are equipped with internal gills to survive aquatic habitats. They have been observed to be most active during twilight; this is believed to be related to the white gypsum composition of the habitat in which they're studied. In laboratory conditions the species is active throughout the day as well, though mainly twilight.

Characteristic category

Habitat

Characteristics
Habitat

Roswell springsnails occur in small, geographically isolated spring-fed habitats set in desert grasslands with gypsum cave and karst features. These systems have permanent, flowing water with natural levels of variation, minimum amounts of contaminants, fluctuating temperatures, and slow to moderate flow velocities. Roswell springsnails have been found in abundance on hard, gypsum surfaces in outflow channels and pools, and the type of substance found in habitats may be an important determining characteristic, similar for other aquatic snails.

Grassland

Ecosystem with large, flat areas of grasses.

Desert

Area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.

Cave or Karst
Lake
River or Stream
Urban
Rural
Wetland

Geography

Characteristics
Geography

The habitat of Roswell springsnail typically occurs in small, geographically isolated spring-fed habitats in the Roswell Artesian Basin of southern New Mexico. These systems have fluctuating temperatures restricted 
Roswell springsnail have been found in abundance on hard, gypsum substrate in outflow channels and pools, and substrate type may be important, similar to other aquatic snails.
 

Import/Export

This species and its parts are not available to import or export. 

Range

Roswell springsnail has been known to occur from localities in Chaves County, New Mexico, including the Berrendo River and a spring on the Roswell Country Club. Habitat alteration has restricted its range to locations primarily associated with Bitter Lake National Wildlife Refuge. Two areas of Critical Habitat totaling 70.2 acres (28.4 hectares) have been designated for Roswell springsnails. One area is shared by Bitter Lake National Wildlife Refuge and land owned by the City of Roswell, and the second is a spring complex on Bitter Lake National Wildlife Refuge owned by the U.S. Fish and Wildlife Service.  

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