TitleVisceral nodular cartilaginous metaplasia in rockfishes (Sebastes spp.) in the eastern North Pacific Ocean.
Publication TypeJournal Article
Year of Publication2002
AuthorsHeidel, JR, Nowak, BF, Fischer, KA, Watral, VG, Kent, ML
JournalJournal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc
Date Published2002 Nov

Multiple, discrete, nodular foci of cartilaginous metaplasia were found in the spleens and kidneys of rockfishes taken from the northeastern Pacific Ocean during a survey to determine the incidence and the nature of diseases in these animals. These nodules sometimes occurred in association with granulomatous inflammation and distinct granulomas. Many of these fish were infected by Ichythophonus spp. or acid-fact bacteria (presumably Mycobacteria spp.). Some of the metaplastic foci contained encapsulated accumulations of eosinophilic vesicles and basophilic granular debris, described by other authors as "cysts of unknown etiology," which have been observed at different sites in a variety of temperate and tropical fish species.