Coriocella hibyae

Coriocella hibyae, also known as the velvet snail, is a species of marine gastropod mollusk in the family Velutinidae.

Although it has a shell, it remains hidden within the folds of the mantle, making the mollusk resemble a sea slug rather than a typical snail. Its appearance mimics a sea sponge, providing effective camouflage in its natural habitat.

This species can grow up to 10 cm in length. Its body is more slug-like, with five finger-like projections on its dorsal side. Its coloration ranges from slate blue to dark brown, often speckled with small black spots, further enhancing its sponge-like disguise. The fragile, ear-shaped shell is entirely enveloped by the fleshy mantle.

Coriocella hibyae inhabits the Indian Ocean and the western Pacific, typically found alone or in pairs among rubble, sand, coral, and rocky reefs in shallow waters.

A carnivorous species, it preys on sponges and other sessile marine organisms.

It relies on mimicry, blending with sponges or corals to evade predators. Like many sea slugs, it can secrete defensive chemicals as a deterrent.

Nocturnal by nature, it remains hidden among reefs during the day, becoming active at night.