Mimic cavesnail

Mimic cavesnail

Critically Imperiled  (NatureServe)[2]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Order: Littorinimorpha
Family: Hydrobiidae
Genus: Phreatodrobia
Species:
P. imitata
Binomial name
Phreatodrobia imitata
Hershler & Longley, 1986[3]

The mimic cavesnail, scientific name Phreatodrobia imitata, is a species of very small or minute freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.[4]

Distribution[edit]

This species is endemic to Texas in the United States,[1] where it is known from three wells that penetrate the Edwards Aquifer.[2][5]: 83373  The type locality is Verstraeten Well, Bexar County, Texas.[3]

Description[edit]

The shell has 3.3 to 3.5 whorls.[3] The average height of the shell is 1.01 to 1.03 mm.[3] The operculum is thin and the radula is trapezoidal.[5]: 83373 

Conservation[edit]

The mimic cavesnail was denied federal listing as an endangered species in 2023.[5] Threats to the snail include physical expulsion via wells, loss of aquifer water due to imbalances between recharge and extraction and groundwater contamination.[5]: 83373–83374  The U.S. Fish and Wildlife Service stated that although climate change is likely to reduce aquifer recharge, human extraction will be reduced concomitantly due to existing regulations protecting the aquifer. The Fish and Wildlife Service was unable to conclude whether groundwater contamination will cause significant impacts, due to the snail's benthic habitat within the large volume of the aquifer and the uncertain magnitude of impact of urbanization around the city of San Antonio. Finally, as of 2023, two of the three wells that ejected snails were no longer functioning, and no new wells have been drilled since 1995 in the area of analysis (Bexar County, Texas).[5]: 83373–83374 

References[edit]

  1. ^ a b Bogan, A.E. (1996). "Phreatodrobia imitata". IUCN Red List of Threatened Species. 1996: e.T17077A6797152. doi:10.2305/IUCN.UK.1996.RLTS.T17077A6797152.en. Retrieved 17 November 2021.
  2. ^ a b "Phreatodrobia imitata". NatureServe Explorer An online encyclopedia of life. 7.1. NatureServe. Retrieved 4 June 2023.
  3. ^ a b c d Hershler R. & Longley G. (1986). "Phreatic hydrobiids (Gastropoda: Prosobranchia) from the Edwards (Balcones Fault Zone) Aquifer region, south-central Texas". Malacologia 27(1): 127-172. page 151.
  4. ^ Hershler R. & Thompson F. G. (1990). "Antrorbis breweri, a new genus and species of hydrobiid cavesnail (Gastropoda) from Coosa River Basin, northeastern Alabama". Proceedings of the Biological Society of Washington 103(l): 197-204. PDF.
  5. ^ a b c d e U.S. Fish and Wildlife Service, Species Assessment Team, Ecological Services Program (29 November 2023). "Endangered and Threatened Wildlife and Plants; Seven Species Not Warranted for Listing as Endangered or Threatened Species". Federal Register. 88 (228): 83368–83377. 88 FR 83368