Protein - Sparing Activity of Lipid and Carbohydrate in the Giant African Mudfish, H. longifilis Diets

In two different experiments on lipid and carbohydrate requirement, H. longifilis was fed diets containing 13.68% to 24.66% of lipid, 17.00% to 20.86% of carbohydrates for 56 days. There was positive response in terms of growth of H. longifilis in the various diets fed in the experiments. There was significant variation (P<0.05) in the specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER), apparent net protein utilisation (ANPU) and percentage survival (PS) in the fish fed varying lipid levels. As for the fish fed varying levels of carbohydrates, there was no significant variation (P>0.05) in the SGR and FCR but there was significant variation (P<0.05) in the PER, ANPU and PS. The protein/lipid ratio was 1.58 while the protein/carbohydrate ratio was 2.22. These ratios are very important in the formulation of H. longifilis feed for optimal growth of fish in that protein is spared for growth while the lipid and carbohydrate portions of the diet are used for energy production. @JASE

Participatory diagnosis and adaptive management of small-scale fisheries in the Niger River Basin

In a broad sense, analysis of ‘resilience’ is about the capacity of systems to adapt to shocks, recognizing that disturbance and change are integral component of complex systems. More formally, resilience analysis proposes to focus on mechanisms and processes that help systems absorbing perturbations and shocks, and coping with uncertainty and risks. Defined in such a way, the concept of resilience thus appears particularly useful for the management of small-scale fisheries. However, while the resilience concept is appealing, particularly in the face of the failure of current management approaches, the danger is that it remains largely academic and theoretical, and not of a great help in effectively improving the way natural resources are managed on the ground. The challenge, therefore, lies in a pragmatic approach to operationalizing the concept of resilience and making its implementation on the ground practical and meaningful. In this project we propose a framework aimed at this objective and we test it in the specific context of small-scale fisheries in the Niger River Basin

Current diversity of aquatic macrophytes in nigerian freshwater ecosystem

In Nigerian inland waters, eight aquatic plants have been incriminated as weeds. From the current study, the most prevalent of these weeds are water hyacinth and cattail plants. These aquatic weeds, once it invades a water body, not only disrupts the ecology of the systems but adversely affects the sociological, cultural and economic realities of the local communities within the area, especially the artisanal fisher folks. This paper showcases aquatic weeds distribution country wide based on its hydrological areas as well as their controlling methods. These methods, when employed in aquatic weed infested water bodies, will manifestly contribute to the success of approaches geared to solving aquatic weed problems

Lake drying and livelihood dynamics in Lake Chad: unravelling the mechanisms, contexts and responses

This article examines lake drying and livelihood dynamics in the context of multiple stressors through a case study of the ‘‘Small Lake Chad’’ in the Republic of Chad. Livelihoods research in regions experiencing persistent lake water fluctuations has largely focused on the wellbeing and security of lakeshore dwellers. Little is known about the mechanisms through which lake drying shapes livelihood drawbacks and opportunities, and whether locally evolved responses are enhancing livelihoods. Here we address these gaps using empirical, mixed-methods field research couched within the framework of livelihoods and human well-being contexts. The analysis demonstrates that limited opportunities outside agriculture, the influx of mixed ethnic migrants and the increasing spate of violence all enhance livelihood challenges. Livelihood opportunities centre on the renewal effects of seasonal flood pulses on lake waters and the learning opportunities triggered by past droughts. Although drying has spurred new adaptive behaviours predicated on seasonality, traditional predictive factors and the availability of assets, responses have remained largely reactive. The article points to where lake drying fits amongst changes in the wider socioeconomic landscape in which people live, and suggests that awareness of the particularities of the mechanisms that connect lake drying to livelihoods can offer insights into the ways local people might be assisted by governments and development actors

Detoxifying effect of Nelumbo nucifera and Aegle marmelos on hematological parameters of Common Carp (Cyprinus carpio L.)

The objective of this study was to investigate the efficacy of Nelumbo nucifera and Aegle marmelos on common carp exposed to sub-lethal concentrations of combined heavy metals (5 ppm) under laboratory conditions. The fish were treated with Nelumbo nucifera (500 mg/kg bwt) and Aegle marmelos (500 mg/kgbwt) for 30 days as a dietary supplement. The blood biochemical parameters of the fish were evaluated by analyzing the level of red blood cells (RBC), packed cell volume (PCV), hemoglobin concentration, glucose, cholesterol, iron and copper. The findings of the present investigation showed significant increase in hemoglobin (p<0.001), RBC (p<0.01) and PCV (p<0.01) of herbal drug-treated groups compared with metal-exposed fish. Conversely, glucose and cholesterol level in blood of common carp showed significant reduction compared with heavy-metal-exposed groups. All the values measured in Nelumbo nucifera and Aegle marmelos treated fish were restored comparably to control fish. Our results confirmed that Nelumbo nucifera and Aegle marmelos provide a detoxification mechanism for heavy metals in common carp

Protein - Sparing Activity of Lipid and Carbohydrate in the Giant African Mudfish, H. longifilis Diets

In two different experiments on lipid and carbohydrate requirement, H. longifilis was fed diets containing 13.68% to 24.66% of lipid, 17.00% to 20.86% of carbohydrates for 56 days. There was positive response in terms of growth of H. longifilis in the various diets fed in the experiments. There was significant variation (P<0.05) in the specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER), apparent net protein utilisation (ANPU) and percentage survival (PS) in the fish fed varying lipid levels. As for the fish fed varying levels of carbohydrates, there was no significant variation (P>0.05) in the SGR and FCR but there was significant variation (P<0.05) in the PER, ANPU and PS. The protein/lipid ratio was 1.58 while the protein/carbohydrate ratio was 2.22. These ratios are very important in the formulation of H. longifilis feed for optimal growth of fish in that protein is spared for growth while the lipid and carbohydrate portions of the diet are used for energy production. @JASE

Comparative Evaluation of the Effectiveness of some local Fabrics for Zooplankton Harvest

A comparative evaluation of the effectiveness for zooplankton harvest for three local fabrics (a white poplin, 120\u3bcm; grey baft, 200\u3bcm; a nylon, 235\u3bcm) and an imported standard zooplankton net of mesh size 76\u3bcm were tested in this study. Mesh sizes and gauze constitution of the fabrics were determined with an ocular micrometer under a compound microscope. Filtration efficiency and clogging rates of the fabrics were also measured. All fabrics were effective in harvesting species of the copepods, the cladocerans and the large-sized rotifer, Asplanchna . The grey baft and the nylon net were not effective in harvesting the small-sized rotifer species like Keratella , Filinia and Trichocerca . All the fabrics effectively harvested Moina , an excellent freshwater cladoceran for fish larval-rearing. Clogging rate was found to be a function of gauze constitution, while filtration efficiency was an index of both gauze constitution and mesh size of fabrics. @ JASE

Comparative Evaluation of the Effectiveness of some local Fabrics for Zooplankton Harves

A comparative evaluation of the effectiveness for zooplankton harvest for three local fabrics (a white poplin, 120mm; grey baft, 200mm; a nylon, 235mm) and an imported standard zooplankton net of mesh size 76mm were tested in this study. Mesh sizes and gauze constitution of the fabrics were determined with an ocular micrometer under a compound microscope. Filtration efficiency and clogging rates of the fabrics were also measured. All fabrics were effective in harvesting species of the copepods, the cladocerans and the large-sized rotifer, Asplanchna. The grey baft and the nylon net were not effective in harvesting the small-sized rotifer species like Keratella, Filinia and Trichocerca.All the fabrics effectively harvested Moina, an excellent freshwater cladoceran for fish larval-rearing. Clogging rate was found to be a function of gauze constitution, while filtration efficiency was an index of both gauze constitution and mesh size of fabrics. (Journal of Applied Sciences & Environmental Management: 2003 7(1): 57-60