EFFECTS OF HANDLING STRESS ON IMMUNE FUNCTIONS OF BLACKJAW TILAPIA Sarotherodon melanotheron

Abstract

Immunological responses in blackjaw tilapia Sarotherodon melanotheron exposed to capture and handling
stress were evaluated. The result obtained indicated a significant (P < 0.05) increase in the values of White
blood cell (WBC), from 18.66  3.81 to 24.32  6.88 x 109 L -1 and the differential counts neutrophils 35.13 9.34 to 43.41 11.21%; monocytes 2.40 1.01 to 3.78 1.64% and eosinophils 1.23  0.88 to 2.14  1.11%. There was significant (P < 0.05) reduction in the lymphocytes number from 61.24  12.31 to 49.67  10.74%. There was a positive correlation (P < 0.01) between WBC and the differential counts; an indication that handling procedures in aquaculture can impair fish immunological properties.