International journal of advanced research, Dec 31, 2020
The study was conducted at Kenya Marine Fisheries Research Institute (KMFRI), Sangoro Station, Ke... more The study was conducted at Kenya Marine Fisheries Research Institute (KMFRI), Sangoro Station, Kenya to compare the growth perfomance of Oreochromis niloticusfry under different protein levels in a biofloc system using weight-length regression models and Fulton`s condition factor (K). Fry of initial mean weight 0.07 ± 0.03 g and length 1.30 ± 0.24 cm were randomly stocked in 18 aquarium tanks with capacity of 50 litres at stocking density of one fish Litre-1. The experiment was set in a greenhouse under controlled temperature and dissolved oxygen conditions using aerators and thermostat heaters. The biofloc used glucose and molasses as carbon sources which were assigned at 22%, 27% and 35% crude protein levels randomly to the aquaria. The fish were fed on their daily ration twice a day at 5% body weight for 14 weeks. Physicochemical parameters were recorded daily using a multiparameter meter and water samples collected before fish sampling for nutrient analysis. A sample of 30 fish per tank were used for taking body weight and total length measurements using an electronic balance and a measuring board respectively. Fry in all treatments exhibited allometric growth with b coefficient varying between 2.54 and 2.66. Average Fultons condition factor ranged between 1.77-1.84 with no significant difference (P>0.05)among the protein levels and the bioflocs. The condition factor showed both carbon sources were suitable for use in the biofloc system and hence replacement of higher protein level (35%) with lower protein level (22%) to reduce the production cost is a feasible application of the biofloc system in fish farming.
Cost of fish production can be reduced by replacement of high-priced fishmeal (FM) with insects s... more Cost of fish production can be reduced by replacement of high-priced fishmeal (FM) with insects sourced ingredients. Four months feed experiment was conducted at a fish farm in Baringo County, Kenya to investigate effects of substituting fishmeal (FM) with black soldier fly larvae meal (BSFLM) on survival and growth performance of C. gariepinus under aquaponic system. Three test diets 35% crude protein content (CP) in which FM was substituted by BSFLM at 25%, 50% and 75% were formulated and experimented with commercial diet of 35% CP. Four weeks old C. gariepinus were stocked in 12 tanks at a density of 50 fish/tank and subjected to the diets. Fish were sampled every three weeks; water parameters were sampled weekly and mortality recorded on occurrence. Diet with 50% BSFLM obtained better FCR for formulated diets with no significance (P<0.05) for FCR and survival. Weight gain of control diet (97.07 g) was significant (P<0.05) compared to formulated diets 64.09g, 69.78g and 67....
Rapid population and economic growth, increased health benefits of aquatic food, and changes in l... more Rapid population and economic growth, increased health benefits of aquatic food, and changes in lifestyles and preferences as a result of rapid urbanization and globalization are all contributing to the rapid growth of aquaculture production in Kenya. Despite significant investment efforts from the national and devolved governments as well as donors and international organizations, smallholder aquaculture production is yet to result in a significant increase in incomes and improved food and nutrition security. We conducted a scoping review to investigate the roles of multilateral development organizations, international financial institutions, and public and private investments in Kenya’s aquaculture subsector. We draw on lessons learned from previous projects implemented at the national, county, and farm levels to make recommendations for sustainable aquaculture intensification in Kenya. To unlock Kenya’s aquaculture potential and improve its food and nutrition status, deliberate e...
The current study assessed the diversity and abundance of phytoplankton genera in two Kenyan salt... more The current study assessed the diversity and abundance of phytoplankton genera in two Kenyan saltworks (Tana and Kurawa) in March and September 2021. Water samples were obtained from ponds with salinities ranging from 30 to 200 ppt by filtering 40 l of water using a 20-μm phytoplankton net. Seventy-six genera of phytoplankton were identified. Genera richness, evenness and diversity decreased with increasing salinity while phytoplankton abundance increased with increasing salinity. Higher phytoplankton densities were observed in the Tana than in the Kurawa saltworks. Ponds of <100 ppt were dominated by Dinophyceae and Bacillariophyceae which accounted for >90 % of the phytoplankton community. Ponds of salinities >100 ppt were dominated by Cyanophyceae which accounted for >90 % of the phytoplankton community. From the results it was concluded that Kenyan saltworks host diverse phytoplankton genera whose richness decreases with increasing salinity and varies with seasons. T...
Aquaculture, being the fastest growing food sector, is expected to provide the highly needed anim... more Aquaculture, being the fastest growing food sector, is expected to provide the highly needed animal protein for about 9.7 billion people globally by 2050. The world population is likely to consume 178 million tons of food fish/aquatic animals by 2028, whereby 58% of fish will likely be from aquaculture. Growth of food fish production is expected to increase overall production of aquafeeds to over 87 million tons by 2025. Aquafeed production relies largely on fishmeal which is getting expensive due to its multiple use and scarcity. A remedy to this situation is the use of non-conventional protein sources, which may be of plant (leaves, cereals, pulses etc.) or animal (insects, worms, etc.) origin. This paper demonstrates the potential of non-conventional ingredients for aquaculture. It was found that crude protein levels of selected non-conventional plant ingredients ranged from 25-71% while those of animal origin were from 66-72%. Inclusion levels of 5-40% and 25-66% were recommende...
Riverine ecosystems are continuously been compromised by human activities resulting in threatenin... more Riverine ecosystems are continuously been compromised by human activities resulting in threatening their integrity. In this study, integrity of Upper Victoria Nile River was assessed using habitat quality and fish biotic indices. Experimental gillnetting was done bi-annually in 9 stations along the river from 2008 to 2018. Nine habitat metrics were used to estimate habitat quality index at every sampling station. Fish sampled, were sorted, identified to species level, and weighed. Counts of introduced and indigenous as well as tolerant and intolerant species were recorded to generate species richness. A total of 10.642 fish, 65 species belonging to nine families were recorded. Dominant species were Lates niloticus 62.79%, Oreochromis niloticus 23.51%, Mormyrus kannume 13.64%; other species were ≤0.06%. Tolerance and trophic guild showed carnivores (61.5%), omnivores (21.5%) and detrivores (16.9%).Mean habitat quality index, total fish catch and fish-based index of biotic integrity v...
This study investigated the effect of biofloc and green water conditions on the survival, growth,... more This study investigated the effect of biofloc and green water conditions on the survival, growth, reproductive traits, and fatty acid composition of the brine shrimp Artemia franciscana. Artemia was cultured in glass jars using three replicated treatments, that is, Control (7.0 × 106 cells ml−1 of freshly cultured Tetraselmis tetrathele), green water technology—GWT (control + 0.5 g/L of chicken manure extract [CME]) and biofloc technology—BFT (GWT + molasses). Artemia cysts were hatched and batch cultured in a 1‐L glass jar containing 500 ml of natural seawater, stocked at 2 nauplii/ml. In the first 2 days, Artemia was fed with fresh T. tetrathele for conditioning, after which each treatment was applied daily until the end of the experiment. Artemia cultures were maintained at 28.0 ± 1°C using an electrically heated water bath system with constant aeration and light (2000 lux) for 30 days. There was higher Artemia survival in BFT (91.3 ± 3.2%) cultures than GWT (78.1 ± 2.9%) and Con...
This study investigated the effect of replacing soybean meal (SBM) with black soldier fly larvae ... more This study investigated the effect of replacing soybean meal (SBM) with black soldier fly larvae meal (BSFLM) on the growth performance, feed utilization, carcass body composition, and amino acids profile of Nile tilapia (Oreochromis niloticus). Three isonitrogenous (30% crude protein) diets containing BSFLM in varying proportions of 0% (BSFLM0), 50% (BSFLM50), and 100% (BSFLM100), were formulated to replace SBM. A commercial diet (COMM0) sourced from the local market was used as a positive control. Male sex-reversed O. niloticus juveniles of a mean weight 20.88 ±0.16 g were stocked in 12 cages each at a density of 12.5 fish m-3. Fish were hand-fed at 5% (28 days), 3% (54 days), and 2.5% (84 days) of the body weight twice a day (1000 hrs and 1600 hrs). Significant differences (P < 0.05) were found in the final body weight, body weight gain (BWG), specific growth rate (SGR), feed conversion ratio (FCR), survival rate, and condition factor (K). The best growth performance and feed ...
This study evaluated the effect of biofloc technology (BFT) on protein utilization and growth per... more This study evaluated the effect of biofloc technology (BFT) on protein utilization and growth performance of Oreochromis niloticus fry under green house for 14 weeks under a 3 × 2 factorial design involving three crude protein (CP) levels (22, 27 and 35%) and two different carbon sources. Molasses and glucose were independently used as carbon sources in the BFT tanks with aeration using air stones. Mono‐sex fish fry of mean weight 0.07 ± 0.01 g and total length 13.1 ± 0.01 mm were stocked at density of 1 fish per litre. The fishes were fed on the three commercial diets that were randomly assigned in triplicates, with the control treatment being 35% CP. Feeding was done twice daily at 5% body weight, while sludge was siphoned weekly. Calculations of specific growth rate (SGR), protein efficiency ratio (PER), food conversion ratio (FCR), survival and measurement of water quality parameters were also performed. Protein levels and carbon sources had significant effects (p < 0.05) on ...
International Journal of Fisheries and Aquatic Studies, 2017
The effects of substituting hydrolyzed feather meal for fresh water shrimp meal on growth, appare... more The effects of substituting hydrolyzed feather meal for fresh water shrimp meal on growth, apparent digestibility and body composition in tilapia Oreochromis mossambicus were evaluated under laboratory condition. Five hundred fish were distributed in a completely randomized design with five treatments in quadruplicates with 25 fish (average weight 3.42±1.02g) per tank. The fish were fed isoproteinous (give the % protein level here) diet with increasing inclusion levels of hydrolyzed feather meal (HFM) (0%, 4%, 8%, 10% and 12%) designated as HFM0, HFM4, HFM8, HFM10 and HFM12 respectively. All the fish were fed at ad libitum for 30 days. Results indicated that fish fed the diet containing 10% inclusion level of HFM exhibited a significantly higher growth and nutritional parameters (P<0.05) in terms of mean final weight (8.05± 2.56), specific growth rate (3.67±0.29 g), food conversion ratio (1.97±0.11 g) and mean weight gain (4.9±0.33), compared to the other diets. Final body compos...
International journal of advanced research, Dec 31, 2020
The study was conducted at Kenya Marine Fisheries Research Institute (KMFRI), Sangoro Station, Ke... more The study was conducted at Kenya Marine Fisheries Research Institute (KMFRI), Sangoro Station, Kenya to compare the growth perfomance of Oreochromis niloticusfry under different protein levels in a biofloc system using weight-length regression models and Fulton`s condition factor (K). Fry of initial mean weight 0.07 ± 0.03 g and length 1.30 ± 0.24 cm were randomly stocked in 18 aquarium tanks with capacity of 50 litres at stocking density of one fish Litre-1. The experiment was set in a greenhouse under controlled temperature and dissolved oxygen conditions using aerators and thermostat heaters. The biofloc used glucose and molasses as carbon sources which were assigned at 22%, 27% and 35% crude protein levels randomly to the aquaria. The fish were fed on their daily ration twice a day at 5% body weight for 14 weeks. Physicochemical parameters were recorded daily using a multiparameter meter and water samples collected before fish sampling for nutrient analysis. A sample of 30 fish per tank were used for taking body weight and total length measurements using an electronic balance and a measuring board respectively. Fry in all treatments exhibited allometric growth with b coefficient varying between 2.54 and 2.66. Average Fultons condition factor ranged between 1.77-1.84 with no significant difference (P&amp;gt;0.05)among the protein levels and the bioflocs. The condition factor showed both carbon sources were suitable for use in the biofloc system and hence replacement of higher protein level (35%) with lower protein level (22%) to reduce the production cost is a feasible application of the biofloc system in fish farming.
Cost of fish production can be reduced by replacement of high-priced fishmeal (FM) with insects s... more Cost of fish production can be reduced by replacement of high-priced fishmeal (FM) with insects sourced ingredients. Four months feed experiment was conducted at a fish farm in Baringo County, Kenya to investigate effects of substituting fishmeal (FM) with black soldier fly larvae meal (BSFLM) on survival and growth performance of C. gariepinus under aquaponic system. Three test diets 35% crude protein content (CP) in which FM was substituted by BSFLM at 25%, 50% and 75% were formulated and experimented with commercial diet of 35% CP. Four weeks old C. gariepinus were stocked in 12 tanks at a density of 50 fish/tank and subjected to the diets. Fish were sampled every three weeks; water parameters were sampled weekly and mortality recorded on occurrence. Diet with 50% BSFLM obtained better FCR for formulated diets with no significance (P<0.05) for FCR and survival. Weight gain of control diet (97.07 g) was significant (P<0.05) compared to formulated diets 64.09g, 69.78g and 67....
Rapid population and economic growth, increased health benefits of aquatic food, and changes in l... more Rapid population and economic growth, increased health benefits of aquatic food, and changes in lifestyles and preferences as a result of rapid urbanization and globalization are all contributing to the rapid growth of aquaculture production in Kenya. Despite significant investment efforts from the national and devolved governments as well as donors and international organizations, smallholder aquaculture production is yet to result in a significant increase in incomes and improved food and nutrition security. We conducted a scoping review to investigate the roles of multilateral development organizations, international financial institutions, and public and private investments in Kenya’s aquaculture subsector. We draw on lessons learned from previous projects implemented at the national, county, and farm levels to make recommendations for sustainable aquaculture intensification in Kenya. To unlock Kenya’s aquaculture potential and improve its food and nutrition status, deliberate e...
The current study assessed the diversity and abundance of phytoplankton genera in two Kenyan salt... more The current study assessed the diversity and abundance of phytoplankton genera in two Kenyan saltworks (Tana and Kurawa) in March and September 2021. Water samples were obtained from ponds with salinities ranging from 30 to 200 ppt by filtering 40 l of water using a 20-μm phytoplankton net. Seventy-six genera of phytoplankton were identified. Genera richness, evenness and diversity decreased with increasing salinity while phytoplankton abundance increased with increasing salinity. Higher phytoplankton densities were observed in the Tana than in the Kurawa saltworks. Ponds of <100 ppt were dominated by Dinophyceae and Bacillariophyceae which accounted for >90 % of the phytoplankton community. Ponds of salinities >100 ppt were dominated by Cyanophyceae which accounted for >90 % of the phytoplankton community. From the results it was concluded that Kenyan saltworks host diverse phytoplankton genera whose richness decreases with increasing salinity and varies with seasons. T...
Aquaculture, being the fastest growing food sector, is expected to provide the highly needed anim... more Aquaculture, being the fastest growing food sector, is expected to provide the highly needed animal protein for about 9.7 billion people globally by 2050. The world population is likely to consume 178 million tons of food fish/aquatic animals by 2028, whereby 58% of fish will likely be from aquaculture. Growth of food fish production is expected to increase overall production of aquafeeds to over 87 million tons by 2025. Aquafeed production relies largely on fishmeal which is getting expensive due to its multiple use and scarcity. A remedy to this situation is the use of non-conventional protein sources, which may be of plant (leaves, cereals, pulses etc.) or animal (insects, worms, etc.) origin. This paper demonstrates the potential of non-conventional ingredients for aquaculture. It was found that crude protein levels of selected non-conventional plant ingredients ranged from 25-71% while those of animal origin were from 66-72%. Inclusion levels of 5-40% and 25-66% were recommende...
Riverine ecosystems are continuously been compromised by human activities resulting in threatenin... more Riverine ecosystems are continuously been compromised by human activities resulting in threatening their integrity. In this study, integrity of Upper Victoria Nile River was assessed using habitat quality and fish biotic indices. Experimental gillnetting was done bi-annually in 9 stations along the river from 2008 to 2018. Nine habitat metrics were used to estimate habitat quality index at every sampling station. Fish sampled, were sorted, identified to species level, and weighed. Counts of introduced and indigenous as well as tolerant and intolerant species were recorded to generate species richness. A total of 10.642 fish, 65 species belonging to nine families were recorded. Dominant species were Lates niloticus 62.79%, Oreochromis niloticus 23.51%, Mormyrus kannume 13.64%; other species were ≤0.06%. Tolerance and trophic guild showed carnivores (61.5%), omnivores (21.5%) and detrivores (16.9%).Mean habitat quality index, total fish catch and fish-based index of biotic integrity v...
This study investigated the effect of biofloc and green water conditions on the survival, growth,... more This study investigated the effect of biofloc and green water conditions on the survival, growth, reproductive traits, and fatty acid composition of the brine shrimp Artemia franciscana. Artemia was cultured in glass jars using three replicated treatments, that is, Control (7.0 × 106 cells ml−1 of freshly cultured Tetraselmis tetrathele), green water technology—GWT (control + 0.5 g/L of chicken manure extract [CME]) and biofloc technology—BFT (GWT + molasses). Artemia cysts were hatched and batch cultured in a 1‐L glass jar containing 500 ml of natural seawater, stocked at 2 nauplii/ml. In the first 2 days, Artemia was fed with fresh T. tetrathele for conditioning, after which each treatment was applied daily until the end of the experiment. Artemia cultures were maintained at 28.0 ± 1°C using an electrically heated water bath system with constant aeration and light (2000 lux) for 30 days. There was higher Artemia survival in BFT (91.3 ± 3.2%) cultures than GWT (78.1 ± 2.9%) and Con...
This study investigated the effect of replacing soybean meal (SBM) with black soldier fly larvae ... more This study investigated the effect of replacing soybean meal (SBM) with black soldier fly larvae meal (BSFLM) on the growth performance, feed utilization, carcass body composition, and amino acids profile of Nile tilapia (Oreochromis niloticus). Three isonitrogenous (30% crude protein) diets containing BSFLM in varying proportions of 0% (BSFLM0), 50% (BSFLM50), and 100% (BSFLM100), were formulated to replace SBM. A commercial diet (COMM0) sourced from the local market was used as a positive control. Male sex-reversed O. niloticus juveniles of a mean weight 20.88 ±0.16 g were stocked in 12 cages each at a density of 12.5 fish m-3. Fish were hand-fed at 5% (28 days), 3% (54 days), and 2.5% (84 days) of the body weight twice a day (1000 hrs and 1600 hrs). Significant differences (P < 0.05) were found in the final body weight, body weight gain (BWG), specific growth rate (SGR), feed conversion ratio (FCR), survival rate, and condition factor (K). The best growth performance and feed ...
This study evaluated the effect of biofloc technology (BFT) on protein utilization and growth per... more This study evaluated the effect of biofloc technology (BFT) on protein utilization and growth performance of Oreochromis niloticus fry under green house for 14 weeks under a 3 × 2 factorial design involving three crude protein (CP) levels (22, 27 and 35%) and two different carbon sources. Molasses and glucose were independently used as carbon sources in the BFT tanks with aeration using air stones. Mono‐sex fish fry of mean weight 0.07 ± 0.01 g and total length 13.1 ± 0.01 mm were stocked at density of 1 fish per litre. The fishes were fed on the three commercial diets that were randomly assigned in triplicates, with the control treatment being 35% CP. Feeding was done twice daily at 5% body weight, while sludge was siphoned weekly. Calculations of specific growth rate (SGR), protein efficiency ratio (PER), food conversion ratio (FCR), survival and measurement of water quality parameters were also performed. Protein levels and carbon sources had significant effects (p < 0.05) on ...
International Journal of Fisheries and Aquatic Studies, 2017
The effects of substituting hydrolyzed feather meal for fresh water shrimp meal on growth, appare... more The effects of substituting hydrolyzed feather meal for fresh water shrimp meal on growth, apparent digestibility and body composition in tilapia Oreochromis mossambicus were evaluated under laboratory condition. Five hundred fish were distributed in a completely randomized design with five treatments in quadruplicates with 25 fish (average weight 3.42±1.02g) per tank. The fish were fed isoproteinous (give the % protein level here) diet with increasing inclusion levels of hydrolyzed feather meal (HFM) (0%, 4%, 8%, 10% and 12%) designated as HFM0, HFM4, HFM8, HFM10 and HFM12 respectively. All the fish were fed at ad libitum for 30 days. Results indicated that fish fed the diet containing 10% inclusion level of HFM exhibited a significantly higher growth and nutritional parameters (P<0.05) in terms of mean final weight (8.05± 2.56), specific growth rate (3.67±0.29 g), food conversion ratio (1.97±0.11 g) and mean weight gain (4.9±0.33), compared to the other diets. Final body compos...
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Papers by Erick Ogello