Wednesday 8 October 2014

A new species of Gall Crab from Indonesia and Malaysian Borneo.


Gall Crabs, Cryptochiridae, are colony-forming Crabs inhabiting Coral reefs. They dwell in tunnels within the Coral surface, often at very high population densities, the females causing the Corals to form galls (tumour-like growths) which they use for protection.

In a paper published in the journal Zootaxa on 29 September 2014, Sancia van der Meij of the Department of Marine Zoology at the Naturalis Biodiversity Center in Leiden, the Netherlands, describes a new species of Gall Crab from reefs in Indonesia and Malaysian Borneo.

The new Crab is placed in the genus Opecarcinus and given the specific name cathyae, in honour of Cathy (Catherine) DeGeorge, to mark 15 years of friendship. It was found dwelling on the Coral Pavona clavus and the closely related Pavona bipartita from Sabah State on Borneo east to the Halmahera Islands, though both Corals are much more widespread, Pavona clavus occurring from East Africa and the Red Sea to the islands of the eastern Pacific, and Pavona bipartite is found from East Africa and the Red Sea to the central Pacific, so the Crab could potentially also be much more widespread.

Dorsal and ventral view of Opecarcinus cathyae (A, B) female with regular colour pattern; (C, D) male with pale colour pattern. Van der Meij (2014).

Opecarcinus cathyae is a small Crab with a vase shaped carapace, reaching about 5.5 mm in length, the females growing larger than the males. The Crabs are orange-red to rust in colour, and covered in small setae (hairs), which trap sediment, giving them a mucky appearance. It was found living at densities of up to 200 crabs per square meter on monospecific stands of Coral.

See also…

Freshwater Crabs of the genus Thelphusula have been found across northern Borneo, although they are likely to be more widely distributed on the island, with the known distribution representing better sampling in Sarawak and Sabah (only a single species has been...


Cave Crabs of the genus Orcovita are known from marine caves across the West Pacific. They tend to...

Christmas Island in the eastern Indian Ocean is noted for its distinctive Crab fauna, most notably the abundant Red Land Crab, Gecarcoidea natalis. Another distinctive form on the island is the Blue Crab, which...


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