Fish Diseases Analysis Used as Bioindicators for Water Quality and its Importance for Environmental Monitoring

Species of fish are important vehicles for the transfer of contaminants to human populations, and mayshow the potential exposure to pollutants. They have been used as representative taxocenosis of aquatic ecosystembiotic community and as a environmental quality assessment tool. Its use in environmental monitoring has severaladvantages because they are directly associated with agent stressors. The objective of this study was to relate thehistopathological changes observed and to verify the significance of histological analysis as a method ofhistopathological evaluation in studies carried out in the area. The study also includes the importance of such typeof analysis in environmental change and to efficiently measure the degree of exposure in aquatic organisms tochemical contaminant. For histological analysis the animals were fixed in 10% formaldehyde and then decalcified, dehydrated withethyl alcohol for impregnation and paraffin embedding and cut at 5-7 µm. The sections were stained withHematoxylin and Eosin. Several types of alterations were observed in the specimens, some of them macroscopicallyvisible. The occurrence of this type of alteration is evidence of the presence of pollutants and/or degraded habitatsof the environments and the analysis of the spatial and temporal variation of their frequency of occurrence in theseenvironments represents an important source of evaluation and monitoring of water quality in these environments.