Impact of Heavy Metal Toxicity on Hematology and Glycogen Status of Fish: A Review

In the era of industries the problem of pollution of aquatic resources has become aggravated. Generally because the industries are constructed near the water bodies in order to get rid of waste generated. Mining, agricultural run-offs, domestic/sewage water etc. further add to the pollution. These waste/sewage waters contain heavy metals which in turn accumulate and affect the health of fishes. Heavy metals are readily available for uptake in cationic state, part of a hydroxyl complex or organometallic compound. Previous studies have reported that heavy metals accumulate in different organs of the fish without causing mortality and their effect first appeared in blood. These alterations make fish weak, anemic and vulnerable to diseases. Hence industrialization on the other hand is targeting the major protein source in the form of fish. The exposure to heavy metals causes increase or decrease in hematological indices, as well as decline in the glycogen reserves. Moreover haematologic parameters and glycogen may serve as suitable biomarkers of fish health and can be used as the bioindicators to monitor the quality of aquatic environment. © 2014, The National Academy of Sciences, India.