This study examined the growth response, nutrient utilization, biochemical and haematological properties of Clarias gariepinus juveniles, fed with graded levels of Bacillus subtilis. Five diets were formulated (35% crude protein; 3127 kCal/kg energy), comprising 0 (T1), 20 mg/100g oxytetracycline (T2), 10 5 (T3), 10 7 (T4) and 10 9 (T5) B. subtilis CFU/ml. African catfish, C. gariepinus (n=150; mean weight =94.33±0.67g) were allotted to 15 rectangular tanks and fed experimental diets apparently to satiation for 8 weeks. Growth performance, nutrient utilization, haematological and biochemical parameters were examined using standard methods. The results showed that fish fed with Diet T5 recorded significantly high values for mean weight gain (MWG) (116.67±5.70g), specific growth rate (SGR) (1.58±0.07%) and percentage weight gain (PWG) (133.62±7.47%), while Diet T1 had least values for MWG (89.00±0.58g), SGR (1.36±0.01%) and PWG (94.35±0.91g). Feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly different (p<0.05) across the test diets, with Diet T5 having the best values for FCR (1.17±0.04) and PER (3.27±0.18). No significant differences (p>0.05) were observed in the haematological, AST, ALP and GSH indices between the fish fed graded levels of probiotic and control diets. The excellent growth performance recorded at the highest inclusion level (T5) of B. subtilis showed that the probiotic could be favourably incorporated into the diet of C. gariepinus juveniles.

(MFLS) were evaluated for the Poecilia reticulata in laboratory bioassays. The acute toxicity was evaluated for 96 h while the sub-lethal effects of the two surfactants on the biochemical parameters of P. reticulata were investigated for a 6 -day exposure period. The derived toxicity indices showed that the FLS (96hLC 50 = 0.062ml/L) was 1.37 times more toxic than the MFLS (96hLC 50 = 0.085ml/L) against P. reticulata. Analysis of variance (ANOVA) showed signifi cant difference (p<0.05) in the quantal response of P. reticulata to different concentrations of FLS and MFLS at 24, 48, 72 and 96 h of exposure. The mean tissue protein, triglyceride, glucose and cholesterol ranged from (21.04 -48.54 and 18.06 -58.54mg/dl), (87.43 -154.95 and 85.63 -144.28mg/dl), (33.95 -55.03 and 32.76 -53.15mg/dl) and (37.30 -65.38 and 37.12 -58.11mg/dl) for FLS and MFLS respectively. ANOVA showed signifi cant difference (p<0.05) in the biochemical response of P. reticulata to FLS and MFLS. The implications of these fi ndings are highlighted.

Six diets were produced using graded levels of banana peels (5, 10 and 15% for both ripe (RBP) and unripe (UBP) banana peels) which were compared with the control diet (CTR) containing maize in the diet of C. gariepinus juveniles. Feeds were fed to triplicate groups of ten fish each to satiation thrice daily for ten weeks. There were significant differences (p<0.05) in Mean Weight Gain (MWG) and Specific Growth Rate (SGR) across diets. The CTR had the highest MWG (58.40 ±5.27g) and SGR (1.877±0.09%) while the least values of MWG (25.03 ±1.85g) and SGR (1.106 ±0.05%) were recorded in Diet3 (15% UBP). The Feed conversion ratio, Protein efficiency ratio and Protein intake recorded significant differences (P<0.05) between the CTR and other diets. Similar results were recorded for Profit Index, Incidence of Cost and Economic Investment Cost Analysis. Likewise, analysis of fish organs recorded significant differences (P<0.05) between the CTR and other diets. Though the CTR had the best growth performance, it had the least Profit Index (1.87) while Diet2 (10% RBP) had the highest Profit Index (3.11). Thus, plantain peel is a profitable alternative energy source for partial substitute of maize up to 10% RBP and UBP in diet of C. gariepinus.Farklı oranlarda muz kabuğu içeren 6 adet diyet grubu (hem olgunlaşmış, hem de ham muz kabuğu için % 5, 10 ve 15) üretilmiş ve jüvenil C. gariepinus 'un beslenmesinde mısır içeren kontrol diyet grubu (CTR) ile karşılaştırılmıştır. Yemler 10'ar adet balıktan oluşan 3 tekrarlı deney gruplarına 10 gün boyunca günde 3 kez balıklar doyana kadar verilmiştir. Diyet grupları arasında Ortalama Ağırlık Artışı (OAA) ve Spesifik Büyüme Oranı (SBO) bakımından gözle görülür farklılıklar (p<0.05) tespit edilmiştir. En yüksek OAA (58.40 ± 5.27 g) ve SBO (1.877 ±0.09) kontrol grubunda ölçülürken en düşük OAA (25.03 ± 1.85 g) ve SBO (% 1.106 ±0.05) 3 numaralı diyet grubunda (%15 ham muz kabuğu) tespit edilmiştir. Yem dönüştürme oranı, protein etkinliği ve protein alımı bakımından da kontrol ve diğer gruplar arasında gözle görülür farklılıklar (P<0.05) kayıt edilmiştir. Benzer sonuçlar karlılık indeksi, maliyet etkisi ve ekonomik yatırım maliyet analizinde de gözlemlenmiştir. Aynı şekilde balık organlarının incelenmesinde de kontrol ve diğer diyet grupları arasında önemli farklılıklar (P<0.05) görülmüştür. En iyi büyüme performansı kontrol grubunda görülmesine rağmen en düşük karlılık indeksi (1.87) bu grupta ve en yüksek karlılık indeksi 2 numaralı diyet grubunda (3.11) görülmüştür. Böylelikle olgunlaşmış ve ham muz kabuğunun, C. gariepinus diyetinde mısırla %10'a kadar yer değiştirilebilecek karlı bir alternatif enerji kaynağı olduğu belirlenmiştir.

No abstract

A five-month study in 2001 of an enclosed lagoon, Kuramo Water in southern Nigeria, exposed to urban perturbation describes its physical, chemical and macrobenthic invertebrate characteristics. Of the 16 physical and chemical conditions studied at four sites within the bank-root biotope, only BOD and TDS content were significantly different between sites. The elevated level of these perturbation indicators could be related to the raw and treated domestic sewage released directly into Kuramo Water from point and non-point sources. A total of 16 taxa and 691 macrobenthic individuals belonging to 11 families were recognised at the study sites. A naidid and a chironomid species were the most abundant, occurring in high numbers throughout. Other invertebrate groups occurred in low numbers. The diversity indices calculated supported this trend. The generally low diversity further supports the observation that Kuramo Water is a disturbed environment. The absence of molluscs in the benthic invertebrate samples of this study, compared to their dominance in earlier studies of Kuramo Water, reflects a modification in the habitat resulting from a change in the salinity from brackish to freshwater.