Usually seen covered with sponge which they apply themselves, scorpion spider crabs resemble the closely related species Inachus phalangium, a species of crabs from the north-eastern Atlantic Ocean and Mediterranean Sea.
They are usually seen covered with sponge which they apply themselves. I. dorsettensis resembles the closely related species Inachus phalangium, but has more prominent spines on the carapace. Inachus phalangium, Leach's spider crab, is a species of crabs from the north-eastern Atlantic Ocean and Mediterranean Sea. 
