ISSN: 2577-4050
Authors: Onwujiariri CE*, Okeke PA, Onwujiariri CA and Nwankwo AK
Three different sizes of Black Jaw Tilapia (Sarotherodon melanotheron) were subjected to dimethoate exposure in the laboratory, and changes in their immunology were observed. The fish were treated with the chemical for 15 days at five different concentrations: 0.00 (control), 0.05, 0.10, 0.15, and 0.20 mg/L. The trial involved the assessment of six water quality variables, including temperature, pH, salinity, dissolved oxygen, nitrite, and ammonia. After the experiment, blood samples from the fish were obtained, and standard laboratory procedures were used to look for immunological profiles in them. Based on all the parameters evaluated, the findings indicated that the chemical had a detrimental effect on the organism even at the lower concentration (0.05 mg/L) over the duration of time (15 days). The findings also showed that the values for ammonia and nitrite increased in proportion to the chemical’s concentration. At the same time, the dissolved oxygen levels dropped (P<0.05). While temperature, pH and salinity were all within the same range for every chemical concentration. However, the chemical significantly distorted the immunological profiles of S.melanotheron, with increasing leucocytosis. Following exposure to this chemical, there are substantial decreases (monocytopenia) and significant increases (P<0.05) in the number of each cell type as well as in the number of lymphocytes (lymphocytosis), eosinophils (eosinophilia), and neutrophils (neutropenia). The study showed that the chemical has a dose-dependent effect on the fish’s immune system. Therefore, care should be exercised when applying this chemical in close proximity to an aquatic environment.
Keywords: Pollution; Contaminants; Stress; Fish; Immunology
