Scientists from Senckenberg Research Institute in Dresden and De La Salle University in Manila have discovered four new species of the extraordinarily colorful Insulamon freshwater crab on the island of Palawan, in the Philippines. The various species of purple and red-hued crabs are endemic to only one or a few Philippine islands — 50 percent of the crab species found on Palawan exist only on the island. As the crabs remain dependent on freshwater at all stages of development, they are unable to spread to other islands, causing them to already be endangered by the much-protested mining activities on Palawan.

Continue reading below
Our Featured Videos

palawan ecosystem, red crab, insualmon crab, bright crab, freshwater sealife
Image © Senckenberg

The discovery of the species came as part of the collaborative Aqua Palawana research program, and a paper on the subject was recently published in scientific journal Raffles Bulletin of Zoology. The unique appearance of the crabs is matched by their unusual development — they skip a saltwater larvae stage altogether, and instead develop fully in freshwater. Separated from their relatives for tens of thousands of years, they’ve developed their own distinct species and genera.

As the newly discovered four species are found to be endemic to Palawan, scientists reinforced that the area is an entirely unique environment. Intercontinental Cry explained “[t]he province of Palawan is part of the “Man and Biosphere Reserve” program of UNESCO and hosts 49 animals and 56 botanical species found in the IUCN Red List of Threatened Species. It is also the home of isolated and vanishing indigenous communities.”

Nickel mining operations on the island are already reported to have caused pollution to the Togupon River, releasing unsafe levels of hexavalent chromium, a toxic and carcinogenic chemical into the freshwater on which the crab depends. Additionally, deforestation from mining has been blamed for flooding in the area, while government officials claim that the mining companies restore the areas once work is complete.

Additional mining operations have been approved, in spite of widespread protests “from people of all walks of life, and against the resistance of indigenous peoples,” reports the Senckenberg Research Institute. In 2010 Canadian mining firm MBMI and its Philippine partners were granted approval to expand nickel exploration and mining on Palawan. An online petition opposing expanded mining operations by any company has so far gathered over six million signatures.

Dr Hendrik Freitag from the Senckenberg Natural History Collections in Dresden explained “The smaller the remaining natural habitat the greater is the risk to endemic fauna and flora. Even minor environmental changes can lead to extinctions. It is all the more important to do research in this region and show that the biodiversity of these islands is unique and worth protecting… that’s why our next step is to investigate Palawan’s species-rich freshwater prawns”.

+ Senckenberg Research Institute


All photos © Senckenberg