Echinoecus
Echinoecus is a genus of crabs that live in association with sea urchins. Formerly considered monotypic, the genus is now thought to contain three species:
- Echinoecus nipponicus Miyake, 1939 – Japan, on Heliocidaris crassispina and Pseudocentrotus depressus
- Echinoecus pentagonus – East Africa and Red Sea to Hawaii and French Polynesia, on Diadema savignyi, D. setosum, Echinothrix calamaris and E. diadema, Heterocentrotus mammillatus and Pseudocentrotus depressus
- Echinoecus sculptus – Christmas Island, on ''Colobocentrotus atratus''