Dietary effects of spaghetti waste as maize replacement in the diet of juvenile African catfish, Clarias gariepinus.

A 56-day experiment was conducted with Clarias gariepinus juvenile to evaluate the effects of replacing maize with Spaghetti Waste (SW). Four isonitrogenous experimental diets were formulated by substituting maize with spaghetti waste at different graded levels of 50, 75 and 100%, respectively with a control (100% maize). The experiment was run in triplicate and fish distributed into 21 plastic tanks. The fish were fed to satiation twice daily and water changed every two days to maintain good water quality. The weight of the fish was determined weekly by bulk weighing. The highest mean weight gain (106.40 +/- 4.59 g) and specific growth rate (2.96 +/- 0.07) were recorded in fish fed 100% SW, though no significant difference (p > 0.05) was recorded between the control and other test diets. There was significant increase (p < 0.05) in the feed intake with increased inclusion of the test ingredient. All the analysed blood parameters recorded significant difference (p < 0.05) except in the white blood cell. The proximate composition of carcass recorded significant difference (p < 0.05) for crude protein, while the ether extract and the dry matter were not significantly different (p > 0.05). The highest crude protein (59.33 +/- 0.50) was however recorded in 75% SW inclusion. This study showed that maize can totally be replaced with spaghetti waste without any adverse effect on the growth and health status of C. gariepinus.

Investigation of acute toxicity of pirimiphos-methyl (Actellic, 25%EC) on guppy (Poecilia reticulata, Peters, 1859).

Pirimiphos-methyl is a broad spectrum organophosphate insecticide and potential toxic pollutant in aquatic ecosystems. The acute toxicity of Pirimiphos-methyl (Actellic) was investigated using Guppy (Poecilia reticulata) in a 96 h static renewal laboratory bioassay. Based on probit analysis the LC50 was 0.026, 0.024, 0.022 and 0.019 ml L(-1) at 24, 48, 72 and 96 h, respectively. Analysis of Variance (ANOVA) showed that there was significant difference (p < 0.05) in the quantal response (mortality) of P. reticulata to different concentrations of Actellic at 24, 48, 72 and 96 h of exposure. Actellic insecticide is toxic to fish; therefore its indiscriminate use in aquatic environment should be discouraged.