Du Preez, LouisSmit, Nico2016-03-102016-03-102013Van Preez, L. & Smit, N. 2013. Double blow: alien crayfish infected with invasive temnocephalan in South African waters. South African journal of science, 109(9/10):1-4. [http://sajs.co.za/]0038-23531996-7489 (Online)http://hdl.handle.net/10394/16613Trade in live, freshwater crayfish for ornamental markets, as well as for aquaculture, has grown rapidly and has become the major pathway for the introduction of non-indigenous crayfish species to several countries worldwide. Here we report on the first record of the Australian ‘redclaw’ Cherax quadracarinatus in the natural waters of a game reserve in South Africa. To compound the situation, these redclaw crayfish were infected with a non-indigenous temnocephalan flatworm parasite. Both crayfish and temnocephalan were in full breeding condition, with young. Further spreading of this crayfish to the subtropical, water-rich, northern KwaZulu-Natal Province of South Africa and southern Mozambique is predicted. Not only might the crayfish compete with indigenous aquatic invertebrates but the non-host-specific temnocephalan might transfer to local decapods, such as freshwater crabsenAlien crayfishaquatic healthSouth AfricaCherax quadricarinatusDiceratocephala boshmaiArticle