Keeping up with Imperiled Freshwater Snails

The Freshwater Invertebrate Resource Assessment and Research Unit conducts research on Floridobia species.

       Researchers examining snail samples

No niche is too small when studying Florida’s natural resources. Currently, scientists with the Fish and Wildlife Research Institute are evaluating the population viability and genetic status of imperiled snails within the genus, Floridobia (formally Cincinnatia). Species of this genus are small (2-5 mm in length) and inhabit low-oxygen spring systems. There are 13 known species of Floridobia that live in Florida and of these, 11 species are only found in single-spring systems. One species, Floridobia mica (the Ichetucknee siltsnail) is confined to less than one-tenth of an acre in the Coffee Spring system within the Ichetucknee Springs State Park.  Another species, Floridobia monroensis (the Enterprise siltsnail), was thought to be extinct but was recently re-discovered by FWC, Stetson University and Florida Museum biologists sampling in Benson’s Mineral Spring near Sanford.

The Freshwater Invertebrate Resource Assessment and Research Unit, headquartered in Gainesville, is beginning the second year of a three-year project to determine the distribution, abundance and habitat requirements of these 13 Floridobia species. In collaboration with geneticists, the team aims to establish a baseline for future monitoring efforts. Presently, there are no quantitative data on the current status of these populations. Additional objectives of the project focus on gathering molecular resources to infer evolutionary history for the genus, evaluate species boundaries, and determine patterns of gene flow amongst populations.This research is especially timely because of the current petitions requesting the U.S. Fish and Wildlife Service to list several Florida Floridobia species.

All of Florida’s endemic Floridobia have been designated as Species of Greatest Conservation Need by the FWC and are also ranked as G1 (critically imperiled) by the global conservation system. We know that their habitats are seriously threatened by increasing rates of water withdrawals, habitat destruction, declining water quality, and invasive species. However, most Floridobia species in Florida were only recently discovered (1960s) and described by Dr. Fred Thompson of the Florida Museum of Natural History. Consequently, very little is known about the origin, life history, ecology and tolerances of this group of extremely small snails.

Fieldwork update, February 2016: Recently, the group has conducted quantitative sampling of Floridobia mica in Coffee Spring and found it to be moderately abundant in some habitats (mostly bryophytes), but it is now threatened by the invasive snail Tarebia granifera. Researchers sampled Benson’s Mineral Spring again for Floridobia monroensis and were not able to find a single specimen. Poor habitat and water quality in the spring appears to have affected the abundance of the snail.


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