Biochemical and Hematological Profiles of Common Carp (Cyprinus Carpio) under Sublethal Effects of Trivalent Chromium

Background: In natural waters and/or aquaculture facilities, fish are oftenexposed to chromium waste and demonstrate cumulative deleterious effects. Toour knowledge, there are no studies concerning the effects of trivalent Cr on C.carpio hematology. This study presents hematological and some biochemicalparameters of common carp, Cyprinus carpio, affected by sublethal concentrationof trivalent chromium.Methods: The fish in the experimental aquaria (three replicates each) wereexposed to a sublethal chromium chloride concentration of 2 mg L 1, which wasprepared as stock solution and added depending on the volume of the aquaria toobtain the required concentration. After a period of 28 days, parameters such ashematocrit (Hct), hemoglobin (Hb), lymphocytes (Lym), neutrophils (Neu), totalprotein (TP), albumin, immunoglobulin M (IgM), glucose, red and white blood cells(RBC and WBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin(MCH), and mean corpuscular hemoglobin concentration (MCHC) were examined.Results: Chromium exposure for 28 days significantly (P<0.05) reduced theamounts of Hct, Hb, RBC, WBC, MCH, and MCHC, whereas albumin and glucosesignificantly (P<0.05) increased in the examined fish as opposed to the control.The levels of Lym, Neu, MCV, IgM, and TP were not significantly different (P>0.05)between the Cr-exposed fish and the control.Conclusion: Hematological indices of fish, caused by chromium toxicity to C.carpio, can be secondary responses to toxicants, including exposure to lowconcentrations of heavy metals, which reflect the launch of stress reaction in theaffected fish.