| Echinoecus | |
|---|---|
 | |
| Echinoecus pentagonus | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Clade: | Pancrustacea |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Brachyura |
| Family: | Pilumnidae |
| Genus: | Echinoecus Rathbun, 1894 |
| Type species | |
| Echinoecus pentagonus Rathbun, 1894 | |
| Synonyms | |
|
Proechinoecus Ward, 1934 | |
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 (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)
