SOLITARY ISLANDS
UNDERWATER
RESEARCH GROUP, INC.

Calcinus guamensis
(Wooster, 1984)

Common Name: Guam Hermit Crab

Distribution: Uncommon in the Solitary Islands Marine Park. Distributed throughout the central and western Pacific, including Vietnam and China, to Madagascar and Reunion Island in the western Indian Ocean. In Australia it has been recorded from Western Australia, northern Australia, and eastern Australia, including Lord Howe Island.

Ecological Notes: Observed in intertidal and shallow subtidal zones to depths of 80 m. Individuals sometimes assemble on branches of living coral but can be seen amongst coral rubble and rocks. It inhabits numerous species of small gastropod shells. 

Additional Notes: Calcinus guamensis can be easily distinguished from all other species of Calcinus by its distinctive colouration: it is olive green to pale brown, with black areas on the walking legs, most of the carpi of both chelipeds. The eyestalks are black proximally with a broad pale band distally, the black eyeball with small white spots. It grows to a maximum shield length of around 12 mm, total length 40 mm.

References:

Palomares, M.L.D. and D. Pauly. Editors. 2018. SeaLifeBase. World Wide Web electronic publication. www.sealifebase.org. version (06/2018) https://www.sealifebase.ca/summary/Calcinus-guamensis.html  Accessed 20/08/2023

Invertebrates of the Coral Sea, University of Queensland website at Calcinus guamensis  Accessed 20/08/2023