Ectocommensal protozoan infestations of gills of red swamp crawfish, Procambarus clarkii (Girard), from commercial ponds

Abstract

Crawfish, Procambarus clarkii (Girard), collected from commercial ponds were examined microscopically to determine the presence of ectocommensal protozoans on the gills. The relation between the incidence of gill ectocommensal protozoans and pond water quality was examined. Ninety-four percent of crawfish sampled were infested, with sixty-five percent of the infested crawfish carrying more than 100 ectocommensals per gill filament. Protozoans observed were of the genera Epistylis, Acineta, Lagenophrys, and Cothurnia, the latter being the most prevalent. Significant correlations existed between gill ectocommensal incidence and water quality variables indicative of primary productivity.