Hidden Hermit Crab

Calcinus latens, commonly known as the hidden hermit crab, is a small species within the family Diogenidae. Native to subtropical regions of the Indo-Pacific, including the 🌊 Red Sea, this crab is found at depths ranging from the surface to 95 meters (311 feet). It inhabits various environments such as coral reefs, rocky platforms, sandy and muddy flats, seagrass beds, and mangrove areas.

Typically, the shell size of Calcinus latens ranges from 2 to 7 millimeters (0.08 to 0.28 inches) in length. The species is characterized by olive-green bodies, dark-tipped legs, and asymmetrical claws, with the left claw larger than the right. Males and intersex individuals tend to be larger than females, displaying significant sexual dimorphism. Due to the often low visibility in reef ecosystems, Calcinus latens uses its chemosensory abilities to navigate, protect itself, and find suitable shells, although it sometimes loses shells to its close relative Calcinus laevimanus.

This omnivorous species has a diverse diet, feeding on algae, polychaetes, sponges, echinoderms, molluscs, crustaceans, organic detritus, and carrion. Despite being classified as omnivores, their dietary habits also have carnivorous aspects. In terms of reproduction, Calcinus latens engages in precopulatory courtship behaviors, which involve olfactory and tactile cues, and typically involves indirect sperm transfer.