One of the major challenges of Aquaculture in Nigeria is high cost of feeds. Sargassum fluitans (seaweed) which crept into Badagry coastal waters was assessed for aquaculture potentials for culturing Coptodon zilli and Clarias gariepinus. Sargassum fluitans was analyzed for heavy metals (As, Hg, Cd, Cu, and Pb) and the results showed that S. fluitans from Badagry coastal waters is safe for fish and animal consumption. Therefore, Sargassum-based feeds were formulated as alternative source of replacement for maize in the diet of C. zilli and C.gariepinus Sargassum fluitans were collected by handpicking during low tides from the shores of Suntan Sea Beach, Badagry, Lagos State, Nigeria. The seaweed was washed thoroughly with borehole water, rinsed with distilled water, and sun dried for 1 week. The experimental feeds consists of control (feed ingredients including maize but with no Sargassum meal at all), treatment 1(5% of maize meal (MM) was replaced with Sargassum), treatment 2 (10% of MM replaced with Sargassum), treatment 3(20% of MM replaced with Sargassum), treatment 4(contain only Sargassum as energy source i.e no maize at all).
A total of 180 sub-adult of C.zilli and fingerlings of C.gariepinus were used for the experiment being evenly distributed in nine (9) tanks (of 1000 litre capacity) and stocking rate of twenty (20) fish per tank. The fish fed with 10% Sargassum diet had the least growth performance index (34.60±7.60%), followed by the control (37.15±5.1%) while those fed with Sargassum only (100% maize replacement) had highest performance index (40.14±8.57%). However, there were no significant differences in the Specific growth rate and % survival rate across the five feeding trials. The study has indicated that Sargassum fluitans is a reliable alternative to maize. Sargassum is 100% free and its processing is very cheap. Hence, the Sargassum- based feeds formulated and used for this study has been offered to some practicing farmers for further trials on their farm.
Keywords: Sargassum- based feed, Safety, growth performance.