A study was conducted in Indian catfish magur, Clarias magur (n=24) with an objective to delineate reference range of important humoral innate immune repertories in serum and mucus. For knowing this, a comparative study of innate immune parameters was done in serum and mucus with respect to seasonal (summer vs winter) and size (juvenile vs adult) variation. Serum was collected from individual fish and diluted to a protein concentration of 500 µg mL-1. Reference range of immune parameters in serum was determined to be; myeloperoxidase (0.607-3.999 U mg-1), lysozyme (10.51-64.95 U mL-1), protease (50.76-94.50%), anti-protease (16.86-77.64%) and bactericidal activity (41.62-80.6%). Similarly, mucus was collected from individual fish and its protein concentration was adjusted to 500 µg mL-1. The reference range in skin mucus was found to be; lysozyme (14.65-106.42 U mL-1), myeloperoxidase (0.085-0.877 U mg-1), protease (91.20-97.25%), anti-protease (7.95-36.19%) and bactericidal activity (50.0-90.71%). Comparison of immune parameters in different seasons indicated that both serum and mucus showed significantly higher levels of lysozyme, myeloperoxidase, anti-protease and bactericidal activities in summers whereas protease activity was higher in winters. Likewise, comparison of immune parameters in different age groups indicated that myeloperoxidase activity in serum and anti-protease activity in mucus were significantly higher in juveniles, whereas lysozyme activity in mucus was significantly higher in adults. Rest of the immune parameters in serum and mucus did not show significant variation between juveniles and adults. This reference range of innate immune repertories in C. magur could be useful to understand the differential role of humoral immune parameters in different patho-physiological conditions.