Freshwater Limpet (Ancylus bermudensis)

Organisms in the genus Ancylus are small freshwater limpets. They are aquatic pulmonate gastropods meaning they are air-breathing, freshwater animals in the same family as slugs and snails. These limpets have a lung and a false gill (Pseudobranch) which allows them to breath air and to survive underwater.

Ancylus bermudensis is first described by Edward Guirey Vanatta in the Proceedings of the Academy of Natural Sciences of Philadelphia in 1910. He recorded that the species was rare and describes the shell as follows:

“Shell oval, greatest width in front, high, thin, horn colour, apex with microscopic radial striae, situated near the posterior right margin, anterior slope convex, posterior and right side concave, left side nearly straight. Surface marked with concentric lines of growth and a few obscure radial lines. Alt. 0.90, diam. 1.73, length 3.10mm.”

This species was also previously refered to as Ferrissia bermudensis. It is endemic to Bermuda were it is found in freshwater pond and marsh habitat at Pembroke Marsh. It is listed as Critically Endangered under the Protected Species Act.

Reference:

Vanatta, E. G. 1910. Bermuda Shells. Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 62 No. 3 (Oct. – Dec., 1910) pp. 664-672.

Read the recovery plan for this species:

Outerbridge, M.E. 2020. Recovery Plan for the endemic freshwater molluscs of Bermuda; the limpet Ancylus bermudensis and the pea clam Pisidium volutabundum. Department of Environment and Natural Resources, Government of Bermuda. 23 pages.