
The Effect of Ariel detergent on hatchery-reared Oreochromis niloticus fingerlings obtained from University of Calabar fish farm was investigated in duplicates (A, and B ) using the water soluble fraction of the toxicant under laboratory conditions for 96 hours. Six concentrations (0, 1, 2, 3, 4 and 5mg/l) were prepared from the water soluble fraction of Ariel detergent for the toxicity test. The experimental animals exhibited different percentage mortalities with toxicant concentrations. The 96 hours LC50 for O. niloticus in both batches (A and B) was 0.301mg/l. There was no significant difference in mortality between the both batches of O. niloticus (P>0.05), leading to the conclusion that the WSF of the toxicant had same toxic effects on the test organisms. However, it was observed that the WSF of Ariel detergent had severe impacts on the test water resulting in alterations of the Physico-chemical parameters. The results of the present study suggest that the water soluble fraction of Ariel detergent had severe impacts on the test organism resulting in mortality.