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The present study aimed to assess the appropriate level of replacement of fish meal (FM) with alternative plant sources in the feed fed to Oreochromis niloticus to evaluate the growth performance. Three isoproteinious (40% crude protein) diets were prepared from different ingredients viz., fish meal, corn gluten meal, wheat gluten meal, and bagasse kenna meal. O. niloticus showed a maximum increase in weight as 9. 70, 11.09, 8.53 and 8.32 fortnight with feeding treatment A, B, C and D, respectively. The growth performance of the fish in terms of weight gain, specific growth rate, feed conversion ratio and protein efficiency ratio were found to be significantly (P < 0.05) higher in the fish fed with 20% replacement of fishmeal in diet B. The worst growth performance was observed in fish fed with commercial diet, designated as diet D. It was concluded that the fish meal can be replaced up to 20 percent with other plant protein sources without any negative impact on fish health. The replacement of fish meal with local plant sources (corn gluten meal, wheat gluten meal, soybean meal and bagasse kenna mix) will not only be beneficial to achieve better growth performance in O. niloticus, it will be a value addition as well.Keywords: feed, plant sources, growth, length-weight, economic evaluation.Impacto da substituição de farinha de peixe por uma mistura de diferentes fontes de proteínas vegetais sobre o desempenho de crescimento nas dietas de Tilápia do Nilo (Oreochromis niloticus L.) ResumoO presente estudo teve como objetivo avaliar o nível adequado de substituição de farinha de peixe (FM) com fontes alternativas de plantas na alimentação alimentada a Oreochromis niloticus para avaliar o desempenho do crescimento. Três dietas isoproteiniosas (proteína de 40% de proteína bruta) foram preparadas a partir de diferentes ingredientes, como farinha de peixe, farinha de glúten de milho, farinha de glúten de trigo e farinha de bagaço de bagaço. O. niloticus apresentou um aumento máximo de peso como 9,70, 11,09, 8,53 e 8,32 g durante a 2ª, 2ª, 3ª e 2ª quinzena com o tratamento de alimentação A, B, C e D, respectivamente. O desempenho de crescimento do peixe em termos de ganho de peso, taxa de crescimento específico, razão de conversão alimentar e relação de eficiência protéica foi significativamente maior (P <0,05) nos peixes alimentados com 20% de reposição de farinha de peixe na dieta B. O pior O desempenho do crescimento foi observado em peixes alimentados com dieta comercial, designados como dieta D. Concluiu-se que a farinha de peixe pode ser substituída até 20 por cento com outras fontes de proteína vegetal sem qualquer impacto negativo na saúde dos peixes. A substituição da farinha de peixe por fontes locais de plantas (farelo de milho, farinha de glúten de trigo, farelo de soja e mistura de bagaço de bagaço) não só será benéfica para obter melhor desempenho de crescimento em O. niloticus, também será uma adição de valor.Palavras-chave: feed, fontes de plantas, crescimento, comprimento do peso, avaliação ec...

The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.

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This review attempts to give an account on the recent advances on the killifish Aphanius dispar dispar as a biological control agent for mosquito larvae. Thirty six (36) articles of literature (scientific papers, technical and workshop reports) on this subject covering the period between 1980 and 2009 were reviewed. The larviciding process by using chemicals to control mosquitoes in the past resulted in a very harmful effects on the environment (bioaccumulation of DDT), resistance of mosquito vectors, destruction of non-target organisms and human health hazards. Biological control of mosquito larvae by using fish has shown many advantages over chemicals, but exogenous fishes such as Gambusia affinis may have negative effects on fishes and destroy the local habitat. Eco-friendly indigenous larvivorous fish with less harm to the environment and the local fish fauna is suitable for biological control of mosquito larvae. Furthermore, A. dispar is capable of natural and artificial reproduction to maintain a fish stock in order to eliminate mosquito larvae and protect people from many mosquito borne diseases such as malaria, dengue, rift valley fever (RVF), encephalitis and many others (Suliman, 2010). Hence, the indigenous killifish, A. dispar is found to play this role effectively and efficiently. Problems associated with its artificial breeding and fungal infection of its eggs can be further investigated. In addition to this, integrated methods of biological control should be carried out in order to reach the best targets of mosquito control.