author(s)
Ashaq Hussain Bhat and Samiea Hussein

abstract
To determine the physical and biological status of a fish and response in close association to various biological and environmental factors, various Haematological parameters are of utmost importance. Therefore, aim of the present study conducted during year 2019 to 2020, was to establish various reference values e. g, haemoglobin (Hb) concentration, total erythrocyte count (RBC), total leucocyte count (WBC), Differential leucocyte count viz. as, Neutrophils, Lymphocytes, Thrombocytes, Monocytes, Erythrocyte volume and Erythrocyte osmotic balance were analyzed in Schizothorax niger. The results revealed that the haematological parameters, i.e., Hb, RBCC, WBCC showed significant (P<0.05) differences with respect to habitat. Significantly (P<0.05) higher values of Hb content (13.02g dl⁻¹), RBC count (247 mm⁻³), Haematocrit (0.37%) and Erythrocyte volume(490.35µm³) were higher in reared fish than wild fish throughout the study period, while significantly (P<0.05) higher WBC count (2.66mm^-3), Neutrophils (40%), Lymphocytes (26.37%), Thrombocytes (25.09%), Monocytes (6.03%) and Erythrocyte osmotic brittleness (3.02 g l^-1 NaCl)) was higher in wild fish compared to reared fish. The information generated in the present study gives the basic reference values of haematological parameters of S. niger which will be useful in monitoring the wellbeing status of fish populations.