Summary
A multidisciplinary study was conducted on water from two rivers in the Abruzzo region of Italy. The study highlighted the importance of histopathological investigations in the evaluation of the environmental impact on fish. Brown trout (Salmo trutta fario) from the Aterno river and chub (Leuciscus cephalus) from the Vomano river were sampled in winter and then again in spring. Histopathological investigations of gills, kidneys and livers revealed inflammatory and degenerative lesions, early warning signals of environmental stress. Lesions were evaluated semi-quantitatively and findings were ranked. The histopathological features were compared with results obtained from the analysis of water samples and macroinvertebrates collected in the two rivers (extended biotic index). All results confirmed alterations of the environment.

Keywords
Chubs, Environment, Extended biotic index, Fish, Histology, Pollution, Trout.