In 2015, there was a a report on newly described crayfish. According to the report, the wild population already in decline due to aquarium.
I wonder if it has been imported into Singapore?
Research Article published on ZooKeys by Christian Lukhaup
"Cherax (Astaconephrops) pulcher, a new species of freshwater crayfish (Crustacea, Decapoda, Parastacidae) from the Kepala Burung (Vogelkop) Peninsula, Irian Jaya (West Papua), Indonesia"