Effect of Seasonal Variations in Hematology, Biochemical, Immunity Constituents in Mugil cephalus, Chano chanos, and Arius arius on Southeast Coast of Tamil Nadu, India

The assessment of the effect of seasonal variations on health, hematology, and serum biochemical components of three marine teleost fishes, Mugil cephalus, Chanos chanos, and Arius arius from Kovalam, East Coast Road, Southeast coast of Tamil Nadu, India. The objectives of the study pointed out the effect of seasonal variation on fish health and immunity. During summer and pre-monsoon, a total of 20 samples were collected from each sample, and hematological, biochemical, immunity parameters, and fish health were considered. M. cephalus (L-23.86±1.03; W-171.22±35.42) C. chanos, (L-22.36±1.17; W-163.03±33.32) and A. arius (L-22.62±1.08; W-168.72±35.04) have different length and weight. The WBC, RBC, Hb, and HCT were higher during summer in M. cephalus, C. chanos, and A. arius likewise, these parameters were lower in the pre-monsoon period (P<0.05). The MCV, MCH, MCHC, and ESR of all three species were higher in the pre-monsoon whereas in the summer they decreased. Likewise, leukocytes such as neutrophils, monocytes, lymphocytes, eosinophils, and thrombocytes show minimum levels in the pre-monsoon and attain maximum levels in the summer. Most importantly, in the summer, serum components protein and glucose were higher, while cholesterol and urea were lower, and vice versa. Although IgM and IgG levels (P<0.05) were higher in the summer and declined in the pre-monsoon season. In the lysozyme assay, respiratory burst activity (NBT) (P<0.05) reveals a higher concentration in the pre-monsoon and was lower in the summer. A total of thirteen hematological parameters, six biochemical, and two immunological parameters, and lysozyme and NBT activities showed a significant relationship with fish health throughout the seasonal changes. Based on the findings, M. cephalus shows maximum variations in length, weight, hematology, biochemical, and immunity levels, whereas C. chanos showed minimum variations. Hence the report indicates the seasons mainly impact the physiological status of the fish species.