True crayfish are not native to Singapore .
True crayfish are commonly found as pets , or as an invasive species ( Cherax quadricarinatus ) in the many water catchment areas , and are alternatively known as freshwater lobsters .
True crayfish are not native to Singapore , but are commonly found as pets , or as an invasive species ( Cherax quadricarinatus ) in the many water catchment areas , and are alternatively known as freshwater lobsters .