Manila - Four new species of freshwater crab, bright purple in colour, have been discovered in the biologically
diverse but ecologically threatened Philippines, the scientist who found them said yesterday.
The tiny crustaceans burrow under boulders and roots in streams, feeding on dead plants, fruits, carrion and small animals in the water at night, said Dr Hendrik Freitag of Germany’s Senckenberg Museum of Zoology.
Found only in small, lowlandforest ecosystems in the Palawan island group, most have purple shells, claws and legs tipped red.
”It is known that crabs can discriminate colours. Therefore, it seems likely that the colouration has a signal function for the social behaviour, for example, mating,” Dr Freitag told Agence France-Presse by e-mail.
Describing his discoveries in the latest edition of the National University of Singapore’s Raffles Bulletin of Zoology, he noted that a total of five species were recognised, four of which are new to science.
The carapace or hard shell of the biggest, Insulamon magnum, is just S3mm by 4l.8 mm while that of the smallest, Insulamon porculum, is 33.1mm by 2S.1mm. The two other new species are Insulamon palawense and Insulamon johannchristiani.