Immune parameters, including total immunoglobulin, lysozyme activity, and alternative complement haemolytic 50 (ACH50) activity, were measured. Total immunoglobulin was measured according to Siwicki et al. (1994). Using fish serum, lysozyme activity was estimated as described by Pitaksong et al. (2013), and ACH50 activity was measured according to Sunyer and Tort (1995).