Brain myxoboliasis of common carp

Abstract

The common carp (Cyprinus carpio) originating from Serbian fish ponds was examined for presence of Myxobolus encephalicus. The spores of M. encephalicus were present in blood vessels and meningeal layers. Its presence has been noted in 32-days old carp fingerlings, where in brain blood vessels predominate plasmodium parasites shape. Although, plasmodium does not effect blood vessels obturation as it is in the spore's case, clinical signs which were similar to those in trout, occurred in the 15-30 days old carps. Fingerlings growth rate and conversion ranged normally. Blood test results in fingerlings with high number of spores in brain had similar values to those in unaffected fingerlings. The morbidity percentage was higher for carps up to the one-month old cultured in the ponds serving for older carp winter storage.