Ecotoxicology: A Review of Pesticides Induced Toxicity in Fish

摘要

Throughout the world pesticides are widely employed in agriculture sector in order to elevate crops’ yield with low labour and efforts. Pesticides exposure leads to toxicity in many non-target organisms, fish being one of the most prominent among these. Most of the time acute concentration of these pesticides leads to mortality while sub lethal concentration of these pesticides result in different lethal changes. These changes may be in behaviour of the exposed fish such as change in feeding behaviour, attack or avoiding behaviour and reproductive behaviour, or other types of alterations such as changes in histology (liver, kidneys, gills, muscles, brain, intestine), haematology (RBCs, WBCs or Plasma), anti-oxidant defence system (Glutathione reductase, Peroxidase, Catalase, Superoxide dismutase, Glutathione peroxidase, Glutathione-S-transferase etc.), changes in nutrient profile (Protein, Lipids, Carbohydrates, Moisture content and Ash etc.) and worth of the fish, hormonal or enzymatic alterations, oxygen consumption, and DNA damage or damage at genes level (genotoxicity). Different environmental agencies are working on this aspect and that’s why there are a large number of banned chemicals. Still these chemicals are available in markets. Certain newly synthesized pesticides (insecticides or fungicides etc.) and extensive use of these chemicals are always there to maximize the problem for aquatic organisms especially fish. This article focuses on the same aspect of ecotoxicology and reviews some major induced toxicological aspects of pesticides in fish including behavioural changes, histopathological damages, haematological alterations, biochemical changes, fluctuations in acetylcholinesterase activity, vicissitudes in protein contents, induced genotoxicity, alterations in feeding biology, oxygen consumption and oxygen stress all across the world.