The four species are in the genus Insulamon, including Insulamon palawanense (pictured). The crabs are between one to two inches wide. Only one other species, I. unicorn, was known in the genus, having been found in 1992.
Scientists aren’t sure why the animals are so brightly coloured. Interestingly, dominant males of the I. palawanense species take on a red colour, in contrast to the purple of females and less dominant males. Because their habitats are so small and individual, the crabs are especially vulnerable to the intrusions of man. Degradation of the water quality of the streams, through farm runoff pollution and forestry, will destroy the crabs.
Hopefully the publicity generated from getting these photographs out on the Internet will help drive the necessary protections for these tiny, living gems.