The toxic effect of photosensitizers in particularly hematoporphyrin (HP), photo-pesticides, has been investigated. The results indicated that the 96 hrs LC50 of HP to Nile tilapia, Oreochromis niloticus was 0.4 X 10-5 Mol/l in case of fry fish (2 g) and 0.2×10-3 Mol/l in case of adult fish (50 g). Exposure of adult Oreochromis niloticus to HP lethal concentration (0.2×10-3 Mol/l) for 96 hours and sublethal concentration (0.2×10-4 Mol/l) for 12 weeks, revealed damage in gills, liver and kidney tissues. A significant decrease (at P < 0.01) in growth indices, RBCs, Ht, Hb, serum total protein and total lipids but significant increase (at p < 0.01) in WBCs, glucose level, serum AST, ALT. AP, creatinine and uric acid, in addition to meat quality deterioration (decrease in muscle total protein and total lipids with an increase in muscle water content) compared to that of control fish group were also investigated. The study implies the importance of previous knowledge about the susceptibility of fish and its reproductive season before usage of HP in environmental applications.
Hematoporphyrin, Oreochromis niloticus , Blood picture. Meat quality