Socorro springsnail
Socorro springsnail | |
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Drawing of an apertural view of a shell of Pyrgulopsis neomexicana. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Caenogastropoda |
Order: | Littorinimorpha |
Family: | Hydrobiidae |
Genus: | Pyrgulopsis |
Species: | P. neomexicana
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Binomial name | |
Pyrgulopsis neomexicana | |
Synonyms | |
The Socorro springsnail,
This tiny snail previously inhabited a small group of thermal springs in the State of New Mexico, USA. Its survival is seriously endangered because its habitat is both vulnerable and severely threatened. The current status of the population of this snail and its habitat area is unknown. The Socorro springsnail has been listed as endangered by the governments of the United States and New Mexico.
Very little is known about this snail in general, because of its minute size, its very restricted range, and the fact that the places where it currently lives are on private property which allows no access.
Taxonomy
The Socorro springsnail was originally described from
Pilsbry's original
The
continuous, the outer margin regularly arched, inner margin straight, slightly thickened. Length 1.6, diam. 1.3 mm.; longest axis of aperture about 1 mm.A. N. S. P.This species, known by many specimens, is smaller than
Amnicola micrococcus, with a narrow aperture, straight inner lip and less impressed suture. Nearly all of the shells are eroded, the spirebeing deeply corroded in fully adult individuals. This gives an abrupt outline of the suture, in front view.
In 1982, American zoologist John B. Burch reclassified the Socorro springsnail as Fontelicella neomexicana.[6] In 1987, two other American zoologists, Robert Hershler from the National Museum of Natural History and Fred Gilbert Thompson from the Florida State Museum (now the Florida Museum of Natural History) assigned members of the genus Fontelicella, including F. neomexicana, to the genus Pyrgulopsis.[5][7]
Description
The Socorro springsnail has an elongate-ovate conical shell that is light tan and short-spired, in other words the shell is low and rounded, without much of a pointed "tip" to it.[5][8] The shell has 3.5–4.5 whorls.[9] The protoconch is usually eroded.[9] The internal callus is reddish brown to amber, and the operculum is pale.[5][10] The height of the shell is 1.6–2.3 mm,[9] and its aperture is ovate.
The body, head, snout and tentacles are dark gray to black in color. The tentacles range from black or dark gray at the base, to pale gray at the tips.[5][10] Female snails are larger than males. In the male, the penis has a long glandular strip on the terminal lobe, a long penial gland, and three shorter dorsal glandular strips.[5][10] A detailed description of the reproductive system of this snail species was provided by Hershler in 1994.[9]
The animal respires by using a type of gill known as a ctenidium (a comb-like respiratory apparatus) which in this species has 20 tall and narrow ctenidial filaments.[9]
In all of the species in the genus Pyrgulopsis, the radula (a strong rasping feeding ribbon covered in microscopic teeth) is of taenioglossan type (seven teeth in each row, i.e. one middle, two laterals and 4 marginals.) The radula of Pyrgulopsis neomexicana was described in detail by Hershler (1994).[9]
Distribution
This species is
It is now extinct at the
Ecology
Habitat
The Socorro springsnail is entirely aquatic, occurring in low-velocity (slow-moving) water near spring sources in a thermal habitat, i.e. near hot springs. More precisely, it is found in the uppermost layer of an organic
The principal spring source where the Socorro springsnail is currently found has been impounded (artificially enclosed, blocked off or dammed), and this has reduced the flowing-water habitat to a very small pool. Only one tiny spring source remains, and this has a small improved pool (less than 1 m2 in area), with a water temperature of 17 °C.[5] The species is abundant on rootlets in this pool, but is not found in the ditches and ponds radiating from the spring into irrigation structures. Other mollusks found in the vicinity include Physa mexicana, Lymnaea modicella, and Pisidium casertanum. In 1981, the colony of Socorro springsnails was found to occupy not only the source, but also the outflow tributary about 2.5 m (8 ft) long to an irrigation ditch. No snails were found in the irrigation flow itself however. In 1991, the total population of the Socorro springsnail in the spring outflow was estimated at 5,000 individuals.[5]
The snail had formerly occurred throughout the thermal springs west of the city of Socorro, living in the same habitats as the Socorro isopod Thermosphaeroma thermophilum.
Feeding habits
This species is
Life cycle
The females of the Socorro springsnail are
Threats
The limited range and precise habitat demands of the Socorro springsnail makes this species vulnerable to
This snail species has extremely limited
The population of the Socorro springsnail is thought to be limited to a single pool which is less than 1 m2 in area, and an outflow ditch about 2.5 m (8 ft) in length. Several of the springs that formerly contained the Socorro springsnail have been impounded, and this has eliminated the precise habitat that is critical for the species’ survival.[5]
Perhaps the greatest threat facing this species is the potential loss of water flow. Excessive pumping from the aquifer that supplies water to the springs could destroy both the springs themselves and the species along with them. Potential pollution of the spring could negatively impact this species and perhaps could also cause its extinction.[5] The effects of climate change, if they include widespread drought, decreased spring discharge, or a change in water chemistry, are a newly recognized threat that could eliminate the species.[11]
Conservation
The State of New Mexico listed the Socorro springsnail as endangered, group 2, on March 28, 1985 (Section 17—2—37 through 17—2—46 NMSA 1978).
The locality is on private land and access to the spring has been denied since 1995. Because of this, the recent population numbers are unknown, the status of the habitat is unknown, and the magnitude of current threats is also unknown.
A decision was made by the U.S. Fish and Wildlife Service not to implement the part of the
References
This article incorporates public domain text from reference
- ^ Cordeiro J. & Perez K. (2011). "Pyrgulopsis neomexicana". The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 10 March 2015.
- ^ a b Federal Register 1994. Endangered and Threatened Wildlife and Plants. 50 CFR Part 17.11 & 17.12.
- ^ a b c Pilsbry H. A. (February) 1916. New species of Amnicola from New Mexico and Utah. The Nautilus, volume 29, number 10: 111-112.; Pilsbry H. A. (April) 1917. The Nautilus, volume 30, number 12,plate V, figure 4.
- ^ Taylor D. W. 1983. Report to the state of New Mexico on a status investigation of mollusks in New Mexico. New Mexico Department of Game and Fish, Santa Fe, NM.
- ^ a b c d e f g h i j k l m n o p q r s United States Fish and Wildlife Service (August) 1994. Socorro and Alamosa Springsnail recovery plan. New Mexico Ecological Services State Office, Albuquerque, New Mexico. 24 pp.
- ^ Burch J. B. 1982. Freshwater snails (Mollusca: Gastropoda) of North America. U.S. Environmental Protection Agency, Coctract No. 68-03-1280, EPA-600/3-82-026, 294 pp.
- ^ Hershler R. & Thompson F. G. 1987. North American Hydrobiidae (Gastropoda: Rissoacea): redescription and the systematic relationships of Tryonia Stimpson, 1865 and Pyrgulopsis Call and Pilsbry, 1886. The Nautilus, 101(1): 25-32.
- ^ New Mexico Department of Game and Fish. 1985. Handbook of Species Endangered in New Mexico, Santa Fe, NM.
- ^ a b c d e f Hershler R. 1994. A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae). Smithsonian Contributions to Zoology, 554: 115 pp. Pyrgulopsis neomexicana at pages 54-55.
- ^ a b c d e f Taylor D. W. 1987. Fresh-water mollusks from New Mexico and vicinity. New Mexico Bureau of Mines & Mineral Resources Bulletin 116, Socorro, New Mexico.
- ^ U.S. Fish and Wildlife Service (10 October) 2008. Socorro Springsnail (Pyrgulopsis neomexicana) 5-Year Review: Summary and Evaluation. Albuquerque, New Mexico, 10 pp.
- ^ “List of Threatened and Endangered Species” NMAC 19.33.6.8(G)(1), New Mexico Department of Game and Fish
- ^ U.S. Fish and Wildlife Service. 1991. Endangered and threatened wildlife and plants; final rule to list the Alamosa springsnail and the Socorro springsnail as endangered. Federal Register 56:49646—49649.
External links