27-6-2023 (SINGAPORE) The National Parks Board (NParks) has successfully hatched a critically endangered species of little spotted swamp forest crab, known as Parathelphusa reticulata, in captivity and released them back into the wild in Singapore. The breeding program was designed to boost the population of the crustaceans and establish more colonies in nature sites around the island, as part of efforts to protect rare plants and animals native to Singapore.
The tiny freshwater crabs, which only grow up to 4cm as adults, are elusive and difficult to spot, study, and capture. They are nocturnal and hide by burrowing into the muddy banks of Nee Soon Swamp Forest, Singapore’s last remaining freshwater swamp forest.
Scientists collected 12 adult specimens in 2018 and brought them to NParks’ conservation facility, where they closely observed the species to better understand the optimal environment in which they thrive and breed. The results were a breakthrough as the crabs could adapt well to treated tap water, meaning they could potentially survive in other nature parks outside of Nee Soon Swamp Forest.
Since 2019, researchers have bred two generations of the species, and some baby crabs were returned to Nee Soon Swamp Forest, while 20 others were released at an undisclosed nature park last week. NParks has not revealed the location to prevent the public from hunting for them and threatening their survival. Prior to the release of the crabs, NParks staff tested the adaptability of the crabs with water collected from the new spot, and site research was conducted to ensure that the chosen location has fewer natural predators such as big fishes that may feed on the crabs.
The initiative is part of NParks’ species recovery programme, aimed at safeguarding endemic or threatened native flora and fauna in the country. It is part of a larger plan to conserve the country’s biodiversity, which in turn helps combat global warming. Currently, over 120 plant and animal species are under the recovery initiative, and NParks is looking to grow this number to 160 by 2030. The little spotted swamp forest crab species is crucial to the ecosystem as it feeds mostly on leaf litter, helping to break them down for other wildlife to consume.
“Animals play an important part in the ecosystem because they, for example, function as pollinators or (in the case of these crabs) break down leaf litter and help with the nutrient recycling process,” said Mr Ryan Lee, group director of the NParks’ National Biodiversity Centre. “All in all, it will result in a positive ecosystem service that will provide cleaner air, cooler temperatures and make Singapore more livable.”
The initiative to save the reticulated swamp forest crab species can play a part in combating climate change, and researchers hope that by introducing them to different areas in Singapore, the species could build new colonies elsewhere. These crabs are only found in Nee Soon Swamp Forest, and if something happens to the site, the crabs will be wiped out. By translocating more crabs into other habitats, the hope is that eventually, a population can be established in those areas.
