Endangered crab to get help to make babies

Several uniquely Singaporean crabs are going to get help in making babies.

The River Safari is planning a breeding programme to make sure that some of the world's most endangered freshwater species which are found only in Singapore do not get consigned to history.

The programme is one of the outcomes of last month's two-day roundtable on saving the pebble-size Johora singaporensis crab, which is found only in hill streams at Bukit Timah and Bukit Batok, and nowhere else in the world.

Other rare cousins include the swamp forest crab, found only in Nee Soon swamp forest, and the Johnson's freshwater crab, which lives only in the Central Catchment Nature Reserve.

"They belong to this country, this island, and if they die, this island is also responsible," said crab expert, Professor Peter Ng, who gave J. singaporensis its name.

The trial breeding programme was announced at a public seminar on March 29 by Mr Lee Meng Tat, chief executive of Wildlife Reserves Singapore (WRS), which runs the River Safari.

He added that WRS would also spread public awareness of these threatened species.

Only a smidgen larger than a 50-cent coin, the J. singaporensis crab was first discovered in 1986 at a freshwater hill stream in Bukit Timah. But in 2007, researchers found it had vanished from the original site, possibly due to the stream water there becoming more acidic.

It is still found at other spots at Bukit Timah. Still, it is not known how many are out there as the shy nocturnal crustacean hides under rocks and is hard to find.

Currently, a two-year study by National Parks Board (NParks) and the National University of Singapore (NUS) is assessing its numbers, habitat conditions, how it breeds and how it interacts with other forest creatures.

Dr Lena Chan of NParks' National Biodiversity Centre said the agency has also taken steps to protect the crabs' habitat. It has re-directed a cycling trail and closed off sensitive stream sites to public access.

Assistant Professor Darren Yeo, an NUS freshwater ecology expert who initiated the roundtable, said participants - which included expert crab breeders and the International Union for Conservation of Nature - will also develop a comprehensive conservation plan for the rare crabs.

The plan will be one of the first in the world for any invertebrate, which are animals without a backbone, such as worms and insects.

They will also look for suitable sites to release captive-bred crabs.

But has anyone successfully bred any?

Not yet, said Dr Daniel Ng, an NUS postdoctoral researcher helping to monitor the crabs. Mating behaviour has been seen among crabs in the lab but they have produced no babies, he added.

But, he said, "we are cautiously optimistic that this crab can be saved."

caiwj@sph.com.sg

This article was published on April 7 in The Straits Times.

Get a copy of The Straits Times or go to straitstimes.com for more stories.