Celebrating Christmas Island biodiversity



The Christmas Island Blue Crab, or Discoplax celeste, on display at the museum

The Lee Kong Chian Natural History Museum (LKCNHM) at NUS kicked off a new exhibition this Christmas season with an apt focus on remote Christmas Island and the diverse critters that inhabit it. At just a third the size of Singapore, the tiny island boasts a rich biodiversity with over 200 endemic species of animals found nowhere else on Earth.

Titled “Christmas Island Red”, the special exhibition opened on 19 December and puts the spotlight on crabs. Located in the Indian Ocean south of the island of Java, Christmas Island is well known for the yearly migration of Christmas Island Red Crabs during the wet season, which sees the vermilion crustacean numbering in the millions travel from the forest to the coast to breed.

Lesser known is the endemic Christmas Island Blue Crab, or Discoplax celeste, which migrates one to two months after the Christmas Island Red Crab. Long thought to be a variant of another species, this crab with a light blue carapace was proven in 2012 to be a new distinct species by LCKNHM Head Professor Peter Ng and his collaborator Mr Peter Davie from the Queensland Museum in Brisbane, Australia.

The Christmas Island Blue Crab is one of several discoveries made by the Museum’s researchers over four expeditions to the island from 2010 to 2017, together with collaborators from Australia, Japan and Taiwan. Their adventures out in the field yielded not only interesting specimens for this exhibition, but also uncovered new insights about the volcanic island’s biodiversity. Among the new animals they identified were the yellow-eyed crab, or Chiromantes garfunkel, named after Art Garfunkel and his song “Bright Eyes”; the Christmas Island Cave Prawn or Macrobrachium xmas; as well as a new cave crab Christmaplax mirabilis, all endemic to the island.



The Christmas Island Red Crab, famed for its annual mass migration

For LKCNHM Operations Officer and ichthyologist Dr Tan Heok Hui, who was involved in all four expeditions, his most memorable experience was collecting the symbiotic duo of the helmet urchin and the endemic Christmas Island Urchin Crab. The helmet urchin sports tiny plates of a deep purple hue instead of spines on its body, and inhabits a precarious terrain along wave-battered rocky shores.

Dr Tan described his experience, “The environment is quite remarkable and makes collecting the helmet urchins challenging. You also need the appropriate tools to remove the helmet urchin from the rocks. You use a thin blade to slide it out carefully, all while perched upon jagged rocks and working quickly before the waves come back in.”

“And if you are lucky, you’ll see a tiny crab — the Christmas Island Urchin Crab — hidden on the underside.” A pair of helmet urchin and its urchin crab he collected are among the exhibits on display. “

"We hope visitors will enjoy discovering more about Christmas Island, its connection with Singapore and the importance of conservation.” - Dr Tan Heok Hui

The exhibition also highlighted Singapore’s connection with Christmas Island stretching back to 1888 when it was annexed as part of the Colony of Straits Settlement, before it was later transferred from Singapore to Australia in 1958. Other specimens showcased at the exhibition include the critically endangered Christmas Island Frigatebird, as well as a bat and gecko — the Christmas Island Pipistrelle and Christmas Island Gecko — that are now extinct in the wild.

“We hope visitors will enjoy discovering more about Christmas Island, its connection with Singapore and the importance of conservation,” said Dr Tan.

Located on Level 1M of the museum, the Christmas Island Red exhibition will run till mid-2018.

See media coverage.

This article was first published in NUS News http://www.science.nus.edu.sg/newshub/2315-celebrating-christmas-island-biodiversity



Prof Ng (left) and Dr Tan with the Christmas Island Red Exhibition at LKCNHM


The Christmas Island Urchin Crab Echinoecus Sculptus on the underside of the helmet victim (Photo: Tan Heok Hui)


 Christmaplax mirabilis is a cave crab endemic to Christmas Island, of which only two specimens have been found to date


The Christmas Cave Prawn or Macrobrachium xmas, one of several new species discovered by the LKCNHM tea during their expeditions 


Dr Tan collecting helmet urchins from Anderson's Dale on Christmas Island in September 2017 (Photo: jose CE Mendoza)