Dardanus calidus is a crustacean belonging to the Diogenidae family that is present throughout the Mediterranean Sea, as well as in the Atlantic Ocean from the coasts of Portugal to Madeira, the Azores and the Canary Islands. We can find this species of crab even in rocky bottoms at depths of 100 meters, although between 20 and 30 meters is where they are more frequent.
Dardanus calidus is one of the largest hermit crabs in the Mediterranean, reaching up to 10 cm in size. The part of the body that is visible outside the shell, is bright red with whitish stripes, and has the whole body covered with small yellow hairs. The abdomen of this species, as in all hermit crabs, is soft and is protected by inserting it into shells that will change occasionally as they become smaller. It has two eyes located above thick eye stalks that have a red and white ringed coloration pattern. The left clamp of this species are usually larger than the right; both are dark red in color and have numerous protuberances on the end of the pincers. In fact, these protuberances are what will allow us to differentiate this species from Dardanus arrosor.
The diet of Dardanus calidus is based on small crustaceans, polychaetes and any organic debris it finds, as it is a scavenger species.
It frequently lives in symbiotic association with Calliactis parasitica anemones, in which the anemone protects the hermit crab with its stinging tentacles, while the crab transports the anemone in its shell from one place to another, benefiting the anemone in obtaining food. Normally, each specimen of Dardanus calidus has in its shell two individuals of Calliactis parasitica, although the number may be higher.
During the months of June to August is when Dardanus calidus reproduces sexually. They have separate sexes, and it is common to observe the female specimens during this time carrying numerous eggs under their abdomen.Photos: