Background and Objective: The aim of this study seeks to Compare the effects of Inclusion levels of Potent and Expired Astaxanthin in the Diet of African catfish Clarias gariepinus Fingerlings for Skin and Flesh Pigmentation. Materials and Methods: A 120 fingerlings Clarias gariepinus was used which was procured from a reputable farm in Jos, Plateau State, Nigeria. They were then taken to the Hydrobiology and Fisheries Laboratory of the University of Jos, Nigeria and allowed to acclimatize for three weeks before the feeding started. The experiment involved the use of 19 fibre glass tanks having average capacity of 95 litres. It was run under the flow-through system at 100 ml/min in order to avoid pollution. Results: After a feeding period of eight weeks, increasing the level of astaxanthin (potent and expired) in the feed of Clarias gariepinus fingerlings from 100 (T1) to 150 (T2) to 200g/kg (T3), the concentration of carotene in the skin increased significantly (p < 0.05) between the treatments except for the control. The effect of pigmentation was given in the skin and flesh of Clarias gariepinus fingerlings fed both potent and expired astaxanthin, except that, the potent astaxanthin gave higher effect of pigmentation on both skin and flesh than the expired astaxanthin. Conclusion: It was however, found that, the concentration of astaxanthin in the skin was higher than that in the flesh under every treatment for both potent and expired astaxanthin.

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Indiscriminate dumping of spent dry cell batteries have continuously polluted aquatic environments usually as surface run-offs with deleterious effects on aquatic fauna including Fish. Toxicity effects of water soluble fractions (WSFs) of waste dry cell battery (WDCB) on blood, gills and liver of Clarias gariepinus fingerlings were investigated under laboratory conditions. Acute (96 hr.) and sub lethal (56 days) bioassays were separately conducted on 120no. C. gariepinus fingerlings stocked ten (10) per tank in twelve (12) circular tanks, each in randomized block design. Fish were exposed to acute (0.31, 0.63, 1.25, 2.50 and 5.00 g/L) and sub lethal (0.02, 0.04, 0.07, 0.14, and 0.28 g/L) concentrations with a control (0.00g/L) in replicates. The 96hr. LC50 of WDCB on C. gariepinus fingerlings was 0.84 g/L with upper (1.12 g/L) and lower (0.49 g/L) confidence limits and cumulated to behavioural changes and death of the fish. Significant alterations (P<0.05) in haematological [white blood cells (WBC) packed cell volume (PCV), red blood cells (RBC) and haemoglobin (Hb)] and biochemical [Alkaline phosphatase (ALP), Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT)] parameters of the gills and liver were observed in both toxicity tests. However, no mortality was recorded in sub lethal bioassay. Waste dry cell battery is hazardous to C. gariepinus fingerlings. Therefore indiscriminate disposal of spent dry cell battery should be discouraged in order to safeguard riparian ecosystem and aquatic fauna.