Echinoecus Explained

Echinoecus is a genus of crabs that live in association with sea urchins.^[1] Formerly considered monotypic, the genus is now thought to contain three species:^[1]

• Echinoecus nipponicus Miyake, 1939 – Japan, on Heliocidaris crassispina (Echinometridae) and Pseudocentrotus depressus (Strongylocentrotidae)
• Echinoecus pentagonus (A. Milne-Edwards, 1879) – East Africa and Red Sea to Hawaii and French Polynesia, on Diadema savignyi, D. setosum, Echinothrix calamaris and E. diadema (Diadematidae), Heterocentrotus mammillatus (Echinometridae) and Pseudocentrotus depressus (Strongylocentrotidae)
• Echinoecus sculptus (Ward, 1934) – Christmas Island, on Colobocentrotus atratus (Echinometridae)

Notes and References

1. Diana G. B. Chia . Peter Castro . Peter K. L. Ng . 1999 . Revision of the genus Echinoecus (Decapoda: Brachyura: Eumedonidae), crabs symbiotic with sea urchins . . 19 . 4 . 809–824 . 1549303 . 10.1163/193724099x00529.