Red Hermit Crab

Overview

The Red Hermit Crab (Dardanus calidus) is a prominent crustacean found throughout the Mediterranean Sea and parts of the eastern Atlantic Ocean. As a scavenger, it plays an important role in marine ecosystems by feeding on decaying organic matter along the seafloor.

Distribution & habitat

This species inhabits the eastern Atlantic, ranging from Portugal to Senegal, including the Azores, Canary Islands, and Cape Verde. It is also widespread across the Mediterranean. It typically favors rocky areas, boulders, and seagrass meadows, ranging from shallow coastal waters to depths of over 100 meters.

Appearance

Recognizable by its vibrant red coloration, this hermit crab features hairy, granular legs that often have a "goosebump" texture. It possesses asymmetrical claws, with the left one typically being larger than the right. Its eye stalks are long, ringed, and topped with greyish-black or green eyes. Adults generally reach lengths of 10 to 12 centimeters.

Biology & behavior

Dardanus calidus is primarily nocturnal and solitary. It is well-known for its symbiotic relationship with the sea anemone Calliactis parasitica. The crab often attaches these anemones to its shell; the anemone benefits from food scraps provided by the crab, while the crab gains protection from predators through the anemone's stinging tentacles. As it grows, the crab must periodically seek out larger empty gastropod shells to accommodate its soft abdomen.