Acute-Toxicity of Sodium Chloride (NaCl) on Oreochromis niloticus Fingerlings

A static bioassay was conducted to determine the 96h LC50 of NaCl to Oreochromis niloticus fingerlings (11.58 + 0.13 g) and to describe the histological changes in the gill, heart and kidney. LC50 of O. niloticus fingerlings was determined graphically as 11.33ppt. The fish showed increase hyperactivity exemplified by erratic movement, loss of reflex and hyperventilation during 96 h exposure. Histological examination revealed that gill architecture was destroyed and gill lamellae were fused. The heart showed deformities including perforation and enlargement. The kidney was greatly deformed and discoloured.