Amnicola rhombostomus (Squaremouth Amnicola Snail)

[surroundx]

Cowie, Robert H., Régnier, Claire, Fontaine, Benoît, and Bouchet, Philippe. (2017). Measuring the Sixth Extinction: what do mollusks tell us? The Nautilus 131(1): 3-41.

[koeiyabe]

Formerly confined to creeks and streams along the west side of the St. Johns River in Clay and Putnam Cos., Florida (Burgess and Franz, 1978; Johnson, 1973; Thompson, 1968; 1999), but later confined to about 2000 square km spanning 4 counties in several different waterways in Florida (though all known from records 20 years old or greater), however, a recent survey in 2000 revealed no extant individuals at any of the formerly known sites where the species was previously known as well as no new sites so this species may be extinct (Dave Almquist, FL Natural Areas Inventory, pers. comm., October 2006).

According to Thompson (1968) and the Florida Museum of Natural History's Invertebrate Zoology Master Database, this species occurred in streams and rivers mostly west of the St. John's River in Clay, Putnam, St. John's and extreme southern Duval counties, Florida, USA, although there was at least one record east of the river. It's known range was approximately 2000 square kilometers and there were at least ten occurrences of this species within that range, although it does appear that it was restricted to certain types of waterways with sandy bottoms. Dr. Fred G. Thompson, of the Florida Museum of Natural History and who described the species in 1968, believes this species to be extinct. He did an intensive survey specifically for this species in 2003 and did not find any specimens in any locality in which he had collected it before nor in any of the streams that are crossed by CR209 in Clay County, Florida. It is barely possible that this species had low population levels in 2003 or that for some other reason it was not found. More surveys for this species are needed to ascertain this species' true and present status.

explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.106612/Amnicola_rhombostomus