Effect of Stressors on Haematological and Hormonal Parameters of Garra gotyla gotyla

Abstract

Studies on stress in different species of fish has been widely made but not much has been done in hill stream fishes especially, Garra gotyla gotyla. Haematological and hormonal parameters are the most common stress indicators. In the present study, an attempt has been made to study the effect of stressors natural (Starvation) and anthropogenic (Manganese) on haematological [Total erythrocyte count (TEC), Haemoglobin (Hb), Haematocrit (Hct), Total leucocyte count (TLC) and Differential leucocyte count (DLC)] and hormonal (Cortisol and Glucose) parameters of fish, Garra gotyla gotyla for an experimental period of 9 weeks. Under the effect of natural stressor, starved fishes were found to exhibit significant decline in TEC, Hb, Hct and TLC. DLC when viewed revealed a decrease in lymphocytes, monocytes, eosinophils and basophils whereas neutrophils and thrombocytes rather exhibited an appreciable increase. A significant increase (P<0.01) in cortisol and glucose levels were observed up to 5th week and here after a significant decline was noticed during rest period of experimental duration. Garra gotyla gotyla also depicted significant decline in TEC, Hb and Hct under the effect of manganese toxicity (MnSO4-1.96mg/l). Contrary to RBC dependent parameters (TEC, Hb and Hct) TLC depicted significant increase and among Differential leucocyte count (DLC) lymphocytes, monocytes and eosinophils register an increase but neutrophils, basophils and thrombocyte population exhibit a decline in their number. Cortisol and glucose levels were noticed to increase up to 4th week and after that exhibit a declining trend in their values during the rest period (5th -9th week) of experimental duration.