Cayenne Keyhole Limpet

Diodora cayenensis

Diodora cayenensis is a small to medium-sized sea snail with a distinctive cone-shaped shell that can measure between 15 mm and 50 mm. The shell features a small keyhole-like opening at the top, bordered by a truncate callus with a deep pit. Its coloration can range from white to shades of pinkish gray or brown, sometimes displaying faint rays. This species inhabits the western Atlantic, from New Jersey to Brazil, including the Gulf of Mexico and Caribbean Sea, typically found at depths between 0 and 46 meters, where it attaches to rocks or shells in intertidal and shallow subtidal zones. As a herbivore, the Cayenne keyhole limpet primarily consumes algae, utilizing its radula to scrape these organisms from surfaces like rocks and coral. It can be located in various marine environments, including seagrass beds and hard substrates, and employs a powerful foot to maintain its position against wave action. Diodora cayenensis reproduces through a method called broadcast spawning, where it releases a large number of eggs into the water to improve the chances of fertilization, which is essential in the ever-changing intertidal habitat. Divers may find this species intriguing as it often blends in with rocky backgrounds. Observing them clinging to surfaces can provide insight into their behavior, and their unique shell structure adds interest to underwater photography. Although not assessed by the IUCN, Diodora cayenensis plays a vital ecological role by helping control algal growth and providing refuge for other marine life.