Murray crayfish once thrived in the southern Murray-Darling Basin. The species was found everywhere from the headwaters of the Murray and Murrumbidgee Rivers in the Australian Alps all the way down to Wellington in South Australia. Murray crayfish once thrived in the southern Murray-Darling Basin. The species was found everywhere from the headwaters of the Murray and Murrumbidgee Rivers in the Australian Alps all the way down to Wellington in South Australia. Plants & Animals Ecology Phys.org – latest science and technology news stories