Oreochromis niloticus fish were exposed to cadmium chloride to see how it affects their blood cells. The fish showed lower packed cell volume and reduced red blood cell counts, but higher platelet counts. The size and amount of hemoglobin in their blood cells increased significantly. These changes are likely due to damage to red blood cell membranes, stress-induced release of red blood cells, and lack of oxygen caused by the cadmium chloride exposure.