Incidence of Psorospermium sp. in Several Cultivated Populations of Crayfishes, Procambarus spp. (Decapoda, Cambaridae), in Southern Louisiana

Abstract An organism tentatively classified as Psorospermium haeckeli was found in red swamp crayfish Procambarus clarkii at four culture sites in southwestern (3) and southeastern Louisiana (1) and in white river crayfish Procambarus zonangulus (=P. acutus acutus) at three culture sites in southwestern Louisiana. Incidence was about 70% in P. clarkii and 25% in P. zonangulus. Psorospermium haeckeli was present in all individual populations of P. clarkii sampled, but not in all P. zonangulus populations. Overall abundance was considerably lower than that observed in the European astacid crayfish Astacus astacus. Furthermore, the organism differed in shape, being longer and narrower than the organism found in A. astacus.