Growth performance of Synodontis nigrita raised on different dietary crude protein levels

Synodontis nigrita is an important indigenous species with aquaculture potential. However, this is yet to be achieved due to scanty information on its nutrient requirements. This study investigated the effects of different dietary crude protein levels on growth performance and haematological parameters of S. nigrita. Six hundred S. nigrita (mean weight 10.14 ± 0.04g) were stocked at 50 fish per treatment in four treatments and replicated thrice in concrete tanks. Fish were fed varying levels of experimental diets: 30%, 35%, 40% and 45% crude protein levels. Growth parameters such as weight gain (WG), specific growth rate (SGR), food conversion ratio (FCR) and protein efficiency ratio (PER) and haematological parameters of the fish samples: haemoglobin concentration (HB), packed cell volume (PCV), red blood cell count (RBC) and white blood cell count (WBC) were determined after the feeding trial. The data were analyzed using Statistical Package for Social Scientist (SPSS), Version 11, 2001 and Statistical Analysis Software  (SAS), Version 8, 2001. Duncan’s multiple rage test was used to compare the differences among means. . The WG of fish fed 40% and 45% protein levels (5.73±0.06g and 6.37 ± 0.13g) were significantly higher (p<0.05) than those fed 30% and 35%  protein levels. The SGR of 40% (0.54) and 45% (0.59) protein levels were significantly higher (p<0.05) than fish fed 30% and 35% protein levels. The FCR of fish fed 45% protein level was lower (10.84) compared to other fish fed 30%, 35% and 40% protein levels. The PER of fish fed 30%,35%,40% and 45% protein levels were not significantly different. Haematological data of fish fed 40% and 45% protein levels, Hb(7.06±0.18 and 7.84±0.59g/dl) and RBC(2.68±0.28 and 2.93±0.0410⁶/mm³) were significantly higher (p<0.05) than in fish fed 30% and 35% protein levels. S. nigrita requires high dietary protein level for its successful aquaculture.