Charles Ngugi | KENYATTA UNIVERSITY (original) (raw)

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Papers by Charles Ngugi

Research paper thumbnail of Utilization of Caridina nilotica (Roux) meal as a protein ingredient in feeds for Nile tilapia (Oreochromis niloticus)

Research paper thumbnail of Potential effect of aquaculture promotion on poverty reduction in Sub-Saharan Africa

Aquaculture International, 2007

Research paper thumbnail of Economic profitability of Nile tilapia (Oreochromis niloticus L.) production in Kenya

Aquaculture Research, 2007

Economic profitability of Nile tilapia production in Kenya was analysed using a model that simula... more Economic profitability of Nile tilapia production in Kenya was analysed using a model that simulated individual fish growth and took fish population dynamics in the pond into account. The results suggest that the currently practiced mixed-sex tilapia culture is economically unsustainable. It is suggested that research and extension efforts be geared towards developing monosex Nile tilapia production systems. Nile tilapia culture with African catfish predation should be viewed as an intermediate step towards all-male Nile tilapia culture. This will allow accumulation of both physical and human capital to support all-male tilapia culture. Under all-male culture, economic returns are high enough to justify investment in Nile tilapia culture using borrowed capital. However, the success of monosex culture will depend on the availability and affordability of quality fingerlings and low-cost fish feeds. The results have a wide application in Sub-Saharan Africa where mixed-sex Nile tilapia culture is common.

Research paper thumbnail of Some aspects of the biology of the stargazer mountain catfish, Amphilius uranoscopus (pfeffer); (Siluriformes: Amphiliidae) indigenous to Kenya streams

African Journal of Ecology, 2009

Research paper thumbnail of Consumer Perceptions and Preferences of Wild and Farmed Nile Tilapia (Oreochromis niloticus L.) and African Catfish (Clarias gariepinus Burchell 1822) in Urban Centres in Kenya

Research paper thumbnail of Yields and economic benefits of tilapia (Oreochromis niloticus) and catfish (Clarias gariepinus) polyculture in ponds using locally available feeds

Research paper thumbnail of Development of Nile Tilapia (Oreochromis niloticus) value chain under Governments of Kenya, Germany and Israel trilateral arrangement for increased aquaculture production and conservation of dwindling stocks of Lake Victoria, Kenya

Research paper thumbnail of ON-FARM TRIALS: EVALUATION OF ALTERNATIVE AQUACULTURE TECHNOLOGIES BY LOCAL FARMERS IN KENYA

Research conducted by the PD/A CRSP at Sagana Fish Farm has begun to identify alternative managem... more Research conducted by the PD/A CRSP at Sagana Fish Farm has begun to identify alternative management practices and technologies that may be suitable in the region, but it should not be assumed that results obtained under controlled experi- mental conditions at Sagana are directly transferable to farms in the area. On-farm testing is therefore a logical step in transferring research-based

Research paper thumbnail of The Effect of Three Different Feed Types on Growth Performance and Survival of African Catfish Fry ( Clarias gariepinus ) Reared in a Hatchery

Research paper thumbnail of PD/A CRSP Eighteenth Annual Technical Report

Research paper thumbnail of Growth performance, survival, feed utilization and nutrient utilization of African catfish ( Clarias gariepinus ) larvae co-fed Artemia and a micro-diet containing freshwater atyid shrimp ( Caridina nilotica ) during weaning

Research paper thumbnail of Daily growth of young-of-the-year of the Baringo tilapia, Oreochromis niloticus baringoensis (Trewavas, 1983)

African Zoology, Dec 10, 2011

Research paper thumbnail of Validation of daily growth of African catfish Clarias gariepinus (Burchell 1822) young-of-the-year from Lake Baringo, Kenya

Lakes Reservoirs Research Management, Dec 1, 2010

Research paper thumbnail of Consumer Perceptions and Preferences of Wild and Farmed Nile Tilapia (Oreochromis niloticus L.) and African Catfish (Clarias gariepinus Burchell 1822) in Urban Centres in Kenya

Research paper thumbnail of Analysis of the use of credit facilities by small-scale fish farmers in Kenya

Aquaculture International, 2010

Research paper thumbnail of The constitution, a charter of rights or a bundle of pious platitudes?

Research paper thumbnail of Comparative Study of Hatching Rates of

Research paper thumbnail of Potential effect of aquaculture promotion on poverty Alleviation in Sub-Saharan Africa

Research paper thumbnail of Contribution of catchment and anthropogenic activities to metal bioavailability in the Lake Victoria using sequential extraction and radiotracer analysis

International Journal of Science and Research (IJSR)

Sequential extraction and radiotracer analyses were used to evaluate the geochemical partitioning... more Sequential extraction and radiotracer analyses were used to evaluate the geochemical partitioning of metals (Pb, Cd, Cr, and Cu) in the sediments of Lake Victoria to partition the contribution of catchment areas. Highest total concentration and enrichments of Pb, Cd and Cr occurred near river inlets from polluted urban areas discharging municipal effluents into the rivers. Partitioning coefficient (Kd) of all metals were lowest in lake sediments at the sites receiving water with high concentration of metals, which showed an apparent decrease with increasing metal enrichment. The exchangeable phase and Fe/Mn oxides were the most important binding phases for Pb, Cd and Cr at the sites receiving industrial and municipal wastes, indicating that these sediments were subjected to recent anthropogenic metal pollutants. Cu partitioned in the residual phase at the site with high geological Cu suggesting Cu enrichment from the natural sources. At the reference sites, metals were bound to the ...

Research paper thumbnail of Growth, survival and nutrient utilization of Nile tilapia (Oreochromis niloticus) using cyanophyceae (Arthrospira fusiformis) as replacement of fishmeal based diets

International Journal of Science and Research (IJSR)

Suitability of using cynaophyceae (Arthrospira fusiformis) to replace fishmeal (Caridina nilotica... more Suitability of using cynaophyceae (Arthrospira fusiformis) to replace fishmeal (Caridina nilotica) as a main protein source in the diet of Nile tilapia (Oreochromis niloticus) was investigated at a ratios of: 25%, 50%, 75% and 100%. The five dietary treatments were tested in triplicate in static earthen ponds for 160 days. Growth, Food conversion ratio (FCR), and nutrient utilization in fish fed at 25% and 50% A. fusiformis were better than those fed 75% and 100% A. fusiformis but not significantly different (P > 0.05) from those fed with C. nilotica diets alone. Growth reduction, increased FCR and reduced nutrient utilization occurred with increasing A. fusiformis in the diet beyond 50% inclusion levels. Survival was however better at higher levels of A. fusiformis inclusion. Thus it is possible to replace up to 50% of C. nilotica with A. fusiformis in the diets of O. niloticus.

Research paper thumbnail of Utilization of Caridina nilotica (Roux) meal as a protein ingredient in feeds for Nile tilapia (Oreochromis niloticus)

Research paper thumbnail of Potential effect of aquaculture promotion on poverty reduction in Sub-Saharan Africa

Aquaculture International, 2007

Research paper thumbnail of Economic profitability of Nile tilapia (Oreochromis niloticus L.) production in Kenya

Aquaculture Research, 2007

Economic profitability of Nile tilapia production in Kenya was analysed using a model that simula... more Economic profitability of Nile tilapia production in Kenya was analysed using a model that simulated individual fish growth and took fish population dynamics in the pond into account. The results suggest that the currently practiced mixed-sex tilapia culture is economically unsustainable. It is suggested that research and extension efforts be geared towards developing monosex Nile tilapia production systems. Nile tilapia culture with African catfish predation should be viewed as an intermediate step towards all-male Nile tilapia culture. This will allow accumulation of both physical and human capital to support all-male tilapia culture. Under all-male culture, economic returns are high enough to justify investment in Nile tilapia culture using borrowed capital. However, the success of monosex culture will depend on the availability and affordability of quality fingerlings and low-cost fish feeds. The results have a wide application in Sub-Saharan Africa where mixed-sex Nile tilapia culture is common.

Research paper thumbnail of Some aspects of the biology of the stargazer mountain catfish, Amphilius uranoscopus (pfeffer); (Siluriformes: Amphiliidae) indigenous to Kenya streams

African Journal of Ecology, 2009

Research paper thumbnail of Consumer Perceptions and Preferences of Wild and Farmed Nile Tilapia (Oreochromis niloticus L.) and African Catfish (Clarias gariepinus Burchell 1822) in Urban Centres in Kenya

Research paper thumbnail of Yields and economic benefits of tilapia (Oreochromis niloticus) and catfish (Clarias gariepinus) polyculture in ponds using locally available feeds

Research paper thumbnail of Development of Nile Tilapia (Oreochromis niloticus) value chain under Governments of Kenya, Germany and Israel trilateral arrangement for increased aquaculture production and conservation of dwindling stocks of Lake Victoria, Kenya

Research paper thumbnail of ON-FARM TRIALS: EVALUATION OF ALTERNATIVE AQUACULTURE TECHNOLOGIES BY LOCAL FARMERS IN KENYA

Research conducted by the PD/A CRSP at Sagana Fish Farm has begun to identify alternative managem... more Research conducted by the PD/A CRSP at Sagana Fish Farm has begun to identify alternative management practices and technologies that may be suitable in the region, but it should not be assumed that results obtained under controlled experi- mental conditions at Sagana are directly transferable to farms in the area. On-farm testing is therefore a logical step in transferring research-based

Research paper thumbnail of The Effect of Three Different Feed Types on Growth Performance and Survival of African Catfish Fry ( Clarias gariepinus ) Reared in a Hatchery

Research paper thumbnail of PD/A CRSP Eighteenth Annual Technical Report

Research paper thumbnail of Growth performance, survival, feed utilization and nutrient utilization of African catfish ( Clarias gariepinus ) larvae co-fed Artemia and a micro-diet containing freshwater atyid shrimp ( Caridina nilotica ) during weaning

Research paper thumbnail of Daily growth of young-of-the-year of the Baringo tilapia, Oreochromis niloticus baringoensis (Trewavas, 1983)

African Zoology, Dec 10, 2011

Research paper thumbnail of Validation of daily growth of African catfish Clarias gariepinus (Burchell 1822) young-of-the-year from Lake Baringo, Kenya

Lakes Reservoirs Research Management, Dec 1, 2010

Research paper thumbnail of Consumer Perceptions and Preferences of Wild and Farmed Nile Tilapia (Oreochromis niloticus L.) and African Catfish (Clarias gariepinus Burchell 1822) in Urban Centres in Kenya

Research paper thumbnail of Analysis of the use of credit facilities by small-scale fish farmers in Kenya

Aquaculture International, 2010

Research paper thumbnail of The constitution, a charter of rights or a bundle of pious platitudes?

Research paper thumbnail of Comparative Study of Hatching Rates of

Research paper thumbnail of Potential effect of aquaculture promotion on poverty Alleviation in Sub-Saharan Africa

Research paper thumbnail of Contribution of catchment and anthropogenic activities to metal bioavailability in the Lake Victoria using sequential extraction and radiotracer analysis

International Journal of Science and Research (IJSR)

Sequential extraction and radiotracer analyses were used to evaluate the geochemical partitioning... more Sequential extraction and radiotracer analyses were used to evaluate the geochemical partitioning of metals (Pb, Cd, Cr, and Cu) in the sediments of Lake Victoria to partition the contribution of catchment areas. Highest total concentration and enrichments of Pb, Cd and Cr occurred near river inlets from polluted urban areas discharging municipal effluents into the rivers. Partitioning coefficient (Kd) of all metals were lowest in lake sediments at the sites receiving water with high concentration of metals, which showed an apparent decrease with increasing metal enrichment. The exchangeable phase and Fe/Mn oxides were the most important binding phases for Pb, Cd and Cr at the sites receiving industrial and municipal wastes, indicating that these sediments were subjected to recent anthropogenic metal pollutants. Cu partitioned in the residual phase at the site with high geological Cu suggesting Cu enrichment from the natural sources. At the reference sites, metals were bound to the ...

Research paper thumbnail of Growth, survival and nutrient utilization of Nile tilapia (Oreochromis niloticus) using cyanophyceae (Arthrospira fusiformis) as replacement of fishmeal based diets

International Journal of Science and Research (IJSR)

Suitability of using cynaophyceae (Arthrospira fusiformis) to replace fishmeal (Caridina nilotica... more Suitability of using cynaophyceae (Arthrospira fusiformis) to replace fishmeal (Caridina nilotica) as a main protein source in the diet of Nile tilapia (Oreochromis niloticus) was investigated at a ratios of: 25%, 50%, 75% and 100%. The five dietary treatments were tested in triplicate in static earthen ponds for 160 days. Growth, Food conversion ratio (FCR), and nutrient utilization in fish fed at 25% and 50% A. fusiformis were better than those fed 75% and 100% A. fusiformis but not significantly different (P > 0.05) from those fed with C. nilotica diets alone. Growth reduction, increased FCR and reduced nutrient utilization occurred with increasing A. fusiformis in the diet beyond 50% inclusion levels. Survival was however better at higher levels of A. fusiformis inclusion. Thus it is possible to replace up to 50% of C. nilotica with A. fusiformis in the diets of O. niloticus.

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