Feral populations of the Australian Red-Claw crayfish (Cherax quadricarinatus von Martens) in water supply catchments of Singapore

The Red-Claw crayfish, Cherax quadricarinatus von Martens, is native to freshwater habitats of northern Australia and Papua New Guinea. Owing to its large size and suitability for aquaculture, C. quadricarinatus has been widely translocated around the world. Unfortunately, C. quadricarinatus is also recognised as invasive, having already established feral populations in South Africa, Mexico, Jamaica and Puerto Rico. The hardiness and conspicuous colouration of C. quadricarinatus has also made it popular in the aquarium trade worldwide, including Singapore. Here, we report the establishment of feral populations of C. quadricarinatus in the water supply catchments of Singapore.