Rare Purple Philippine Crabs Discovered

Four new species of freshwater crab were discovered in the Philippines by a team led by Hendrik Freitag of the Senckenberg Museum of Zoology in Dresden, Germany in 2012.

One of the crabs found was this stunning bright purple crab!

This is the Isulamon palwanense Crab. It is endemic to the island of Palawan in the Philippines. Palawan is situated between the Philippines and the Sundaland region. The bright colour is theorised to be an adaption to help them recognise conspecifics. Hendrik Freitag said that "It is known that crabs can discriminate colours. Therefore, it seems likely that the colouration has a signal function for social behaviour, like mating. This could explain why large males of various Insulamon species are more reddish compared to the generally violet females and immature males." They are about 2.5–5.3 centimetres (1.0–2.1 in) wide and live on a diet of decaying fruit and vegetable matter and even occasionally animal carcasses. It typically burrows under rocks, this and its size has contributed to it's ability to stay undiscovered until now. As a freshwater crab on an island surrounded by saltwater it cannot spread to other regions this means their future could be uncertain. According to Freitag  "Their restricted habitat means that even the smallest changes in the environment could have enormous effects on the crabs — possibly driving them toward extinction. The presence of mining operations on the island could represent one such threat. " Although not a marine animal it was such a fascinating and beautiful creature I could not help researching.

Classification

Kingdom -	Animalia
Phylum -	Arthropoda
Subphylum -	Crustacea
Class -	Malacostraca
Order -	Decapoda
Infraorder -	Brachyura
Family -	Potamidae
Genus -	Insulamon
Species -	I. palawanense

References

Freitag, H. (2012). Revision of the genus Insulamon Ng & Takeda, 1992 (Crustacea: Decapoda: Potamidae) with description of four new species. The Raffles Bulletin of Zoology. 60(1), 37-55.