Effects of 2, 2-Dichlorovinyl Dimethyl Phosphate (DDVP) on leukocyte profiles in juveniles and adult sizes of Tilapia guineensis

Most of the vertebrates including fish have five types of white blood cells such as lymphocytes, neutrophils, eosinophils, basophils and monocytes. The shape of each cell type appears to be conserved in living organism, with the exception of the neutrophils.1,2 In aves and reptilia, the neutrophils take the place of heterophils, and carry out the same immunological functions in the cell of these organisms.3 While in amphibians, this category of cell is sometimes called heterophils, however it is comparable to a neutrophil. And reptilian families have a sixth type of cell, called an azurophil, which majority of scientists classify with monocytes.4 Neutrophils/heterophils and lymphocytes constitute about 80% of WBCs in mammals. They are the main phagocytic leukocytes, and multiply rapidly in the system of the fish as a reaction to disease invasion, inflammations, stress and toxicants.5,6