Echinoecus pentagonusis commonly referred to as Sea Urchin Crab, Anal crab. Difficulty in the aquarium: There are no reports available yet that this animal has already been kept in captivity successfully. A aquarium size of at least 100 Liter is recommended. Toxicity: Toxic hazard unknown.
The "sea urchin crab" Echinoecus pentagonus is a species of crab in the family Pilumnidae
Usually inhabits the anal pore of the sea urchin Echinothrix calamaris. Carapace width 1/2 inch. Hawaii & the Indo-Pacific.
Taxonomic synonyms of E. pentagonus include
Echinoecus klunzingeri Miyake, 1939
Echinoecus pentagonus Rathbun, 1894
Echinoecus rathbunae Miyake, 1939
Eumedon convictor Bouvier & Seurat, 1906
Eumedon pentagonus A. Milne-Edwards, 1879
Eumedonus petiti Gravier, 1922
Liomedon pentagonus Klunzinger, 1906