The Striate Bubble, Bulla occidentalis A. Adams, 1850, is a local gastropod that may be seen alive in large numbers during the winter at the east end of Sanibel and other protected areas. Its fragile, barrel-shaped shell may reach 25 mm (one inch). The snail, when active, completely envelops the shell, but may retract completely into it when threatened. The Striate Bubble is a burrower, living in sandy-mud areas. Bubble snails and their relatives are hermaphroditic animals, having functional male and female reproductive systems. The egg masses of Striate Bubbles (photo on right) are gelatinous, enveloping and protecting tiny greenish-yellow eggs.
From left, shell photos by José H. Leal; live snail by Ángel Valdés, taken on Sanibel Causeway; egg mass by Linda Shockley, near Marco Island.