Whirling disease in New Zealand trout caused by myxosoma cerebralis (hofer, 1903) (protozoa: Myxosporida)

Abstract

Examination of diseased rainbow trout (Salmo gairdneri) from a trout hatchery in New Zealand revealed spores of Myxosoma cerebralis. Fish also exhibited the typical signs of infection: “whirling” movements when disturbed, skeletal deformities and tail darkening. Records suggest that the disease may have been present for some years. A brief summary of the parasite's life cycle is given, and recommendations are made for legislation to reduce the possibility of its spread to other hatcheries and to reduce the risk of importing other disease organisms into New Zealand. © 1977 Taylor & Francis Ltd.