Common Hairy Crab

Pilumnus vespertilio

The common hairy crab, a member of the family Pilumnidae, is a small crustacean found in the Indo-West Pacific region, ranging from East Africa to the Philippines and the Great Barrier Reef. It typically inhabits the intertidal to subtidal zones, preferring the lower eulittoral areas on rocks and crevices within fringing coral reefs. This crab is adapted to a shallow depth range of 0 to 3 meters, where it can be seen scuttling across rocky surfaces or hiding in crevices. The common hairy crab is part of the order Decapoda, which is primarily gonochoric, meaning individuals are distinctly male or female. Their reproductive behavior includes a precopulatory courtship ritual, which relies on olfactory and tactile cues, and usually involves indirect sperm transfer. Divers encountering this species might observe these behaviors, especially during mating seasons. While not evaluated for conservation status by the IUCN, the common hairy crab is an interesting species for divers to observe due to its unique habitat preferences and reproductive behaviors. However, it is important to note that this crab is poisonous to eat, so it should not be collected or consumed.