There are no crayfish native to continental Africa, but seven species on Madagascar, all of the genus Astacoides.[6]
Australasia is particularly rich in crayfish. The small genus Paranephrops is endemic to New Zealand. The genera Astacopsis is endemic to Tasmania, while a further two are found on either side of the Bass Strait – Geocharax and Engaeus. The greatest diversity, however, is found on the Australian mainland. Three genera are endemic and have restricted distributions (Engaewa, Gramastacus and Tenuibranchiurus), while two are more widespread and contain more than one hundred species between them: Euastacus, around the Australian coast from Melbourne to Brisbane, and Cherax across Australia and New Guinea. The Tasmanian genus Parastacoides was determined to be a synonym of Geocharax, and is no longer valid.[7]
^Heather D. Bracken-Grissom; Shane T. Ahyong; Richard D. Wilkinson; Rodney M. Feldmann; Carrie E. Schweitzer; Jesse W. Breinholt; Matthew Bendall; Ferran Palero; Tin-Yam Chan; Darryl L. Felder; Rafael Robles; Ka-Hou Chu; Ling-Ming Tsang; Dohyup Kim; Joel W. Martin; Keith A. Crandall (July 2014). "The Emergence of Lobsters: Phylogenetic Relationships, Morphological Evolution and Divergence Time Comparisons of an Ancient Group (Decapoda: Achelata, Astacidea, Glypheidea, Polychelida)". Systematic Biology. 63 (4): 457–479. doi:10.1093/sysbio/syu008. PMID24562813.