Histopathological alterations in the intestine of whitefish {Coregonus sp.) larvae reared on zooplankton from Lake Constance

Abstract

Coregonid larvae suffered high mortality during the first days of feeding when reared on live zooplankton from their natural habitat. Histological studies on 7, 13 and 20 day old larvae suggested that these losses were caused by pathological alterations in the intestine of the larvae. The symptoms observed included epithelial hyperplasia, dysplasia and complete intestinal epithelial necrosis. These changes were compared with the normal histological differentiation found in larvae reared on Artemia nauplii. It is concluded that some component of lake plankton acts as a stressor to the intestinal epithelium and provokes the histopathological alterations which finally lead to the death of the larvae.