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Southwest Florida Shells with Emphasis on Sanibel & Captiva

By José H. Leal

Family Oxynoidae

Lobiger souverbii

P. Fischer, 1857

Souverbie Lobiger

This sea slug reaches about 20 mm (0.78 inch). Its cap-like, open-coiled, translucent shell is very thin, covers only the central-dorsal part of the animal, and is flanked by the four parapodial lobes that are typical of the genus Lobiger. Most likely, the lobes act to increase the apparent size to animal. That, combined with production of a sticky substance, probably acts to intimidate potential predators. The Souverbie Lobiger may be very difficult to observe alive, as it displays cryptic coloration, i.e., the green color of the animal mirrors the color of its habitat and preferred food, green algae in the genus Caulerpa. The shell illustrated in this piece was collected in January 2019 by Ann Palmer, at Cayo Costa. The photo of the live sea slug was taken by Anne DuPont at Lake Worth Lagoon, Palm Beach County.