Acute toxicity of the latex of C. procera on Clarias gariepinus juveniles was measured over a period of 96-h as a management tool in killing predatory fish in earthen ponds in Nigeria. The latex concentrations of 0.0 mg/l, 10.0 mg/l, 22.0 mg/l, 45.0 mg/l, 100 mg/l, 220 mg/l and 1000 mg/l were used under laboratory conditions in plastic aquaria. The 96 h Lc 50 was 64.0 mg/l obtained using graphic and probit methods. The regression equation for the probit curve was y = 2.46x + 0.58 (where probit value = Y, X = log concentration per treatment). Behavioral changes observed during exposure of fish to toxicant include hyperactivity, erratic swimming, imbalance coupled with loss of co-ordination, inclination at the water-air interface, increased opercular beats, clustering and crawling and submergence coupled with paralysis (death). De-pigmentation of the skin increased with increase in latex concentration with a complete bleaching from black/dark brown to pure white occurred at 45.0 and 100.0 mg/l. Histological changes included congestion, haemorrhage, multiple foci of spongiosis of white matter, necrosis and cellular infiltration in the brain tissues. Liver exhibited degeneration, fatty change and infiltration, and generalized haemorrhage. Gill showed congestion of capillaries, keratinization, stunting, necrosis and cell infiltration. The heart-tissues were indifferent to treatments. Histological effects increased in intensity with increase in the concentration of C. procera latex.

In fish farming, nutrition and haematology are critical. The former accounts for 70% production cost and the later determines an excellent health status of fish. Feeding trials were conducted in the laboratory for 12 weeks to evaluate the growth performance and haematological parameters of Clarias gariepinus fed varying levels of Chrysophyllum albidum seed meal (ASASM) as a replacement for maize in diets. The experimental diets were prepared using 0, 25, 50, 75 and 100% C. albidum seed meal to replace maize. The initial weight of the test organism was 28.6 g stocked in rectangular white plastic with 3 replicates for each treatment. The fish juveniles were fed at 5% body weight. In this study, growth performance, feed utilization and haematological parameters were determined. The mean weight gain (MWG), specific growth rate (SGR) and feed conversion ratio (FCR) were significant across the treatments following the direct relationship to inclusion levels (p<0.05). Protein efficiency ratio (PER) and total fish production were all significantly different across the diets (p<0.05). The reductions in PCV and other primary haematological variables (HB, RBC and TWBC) were significant at p<0.05 as the level of inclusion increased. The blood variables showed that the haematopoiesis of the test organism was positively influenced by ASASM; thus impairing blood production. The increase incorporation of African star apple seed meal (ASASM) was stressful to the experimental fish. There is need to further study the phytochemical factors and trials for suitable processing method to justify the targeted economic gains without compromising the health status. Key word: Red blood cell, experimental diets, catfish, feed ingredients, African star apple seed meal (ASASM).

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