Velutin Snail

Coriocella nigra

Coriocella nigra is a distinctive sea snail characterized by its velvety black or brown body, which can reach lengths of up to 10 cm. The mantle is tuberculate, with delicate borders that spread widely, and the dorsal part of the body features four or five lobes. Its triangular, granulated tentacles are spotted with white, and it has brown eyes at their base. This species has an internal shell that is translucent white and smooth, with irregular growth lines, typically measuring between 10 mm and 30–40 mm in length. Divers can recognize it by its unique coloration and internal shell structure, setting it apart from similar gastropods in the region. Coriocella nigra inhabits rocky environments across the Indo-Pacific region, including areas such as South Africa, Madagascar, and Hawaii, typically found at depths ranging from 1 to 15 m. It thrives in both intertidal and subtidal zones, often among specific algae like Halimeda kanaloana in Hawaii. As a carnivorous species, it primarily feeds on tunicates, and its diet may include other small invertebrates. The reproductive behavior involves broadcast spawning, with embryos developing into planktonic larvae before maturing into adults. Encounters with this species during dives can be intriguing, as they often blend into their rocky surroundings. Observing their feeding behavior or interactions with other marine life, such as hermit crabs that may use their shells, can enhance the diving experience. The conservation status of Coriocella nigra is not evaluated, indicating a lack of comprehensive data on its population trends.