Potentials of castor seed meal (Ricinus communis L.) as feed ingredient for Oreochromis niloticus

The potentials of castor seed (Ricinus communis) meal as feed ingredient for Oreochromis niloticus was determined by using boiled seeds to prepare five diets which were fed to the fish species. The effects of the experimental diets on the weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio, apparent net protein utilization, digestibility and carcass composition were investigated. The best of these growth factors were obtained with feed formulated from R. communis seeds boiled for 50 and 65 minutes. The highest carcass protein content was observed with fish fed with 65 minute-boiled seed

A survey of the artisanal fisheries of kontagora reservoir, Niger state, Nigeria

A survey of the artisanal fisheries of Kontagora Reservoir was conducted between January – December, 2007, using statistical frame survey and catch assessment survey. Five fish families made up seven fish species were recorded. The fish species Hemichromis fasciatus, a cichlid was the most dominant with mean value of 414.3 and 7715 in terms of number and weight respectively. Nineteen fishermen using gill nets, cast nets, hook and line sets, and Malian traps as fishing gears were recorded in the reservoir with a total mean catch of 4.40kg/canoe or 167 fishes/canoe. The reservoir was productive and comparable with other smaller but productive African lakes. The monitoring, control and surveillance (MCS) system was suggested for management consideration, with emphasis on registration of fishermen and their fishing equipment, enforcement of minimum marsh size of 3” and establishment of community based cooperative scheme

An assessment of the physico-chemical parameters of Kontagora reservoir, Niger state, Nigeria

The seasonal variations in the physicochemical parameters of water reservoir in Kontagora, Nigeria were studied from January to December, 2007. The physico-chemical parameters were determined bimonthly. They include: temperature (using mercury in glass thermometer), transparency (using Secchi-disc ), while Pye Unicam model 292 meter was used for pH and electrical conductivity determination . Dissolved oxygen by modified Winkler-azide method, water hardness by Lind method and Phosphate – phosphorus by Denges method, total alkalinity by titration method, total dissolved solid by O’wen method, while Nitrate-Nitrogen was determined using Phenoldisulphonic acid method. Water depth was determined using a calibrated measuring tape weighted at one end. The rainy season mean values for water temperature, depth, pH, Nitrate-Nitrogen, were significantly (

Production of earthworm meal for aquaculture

Three soil sample media (loamy, sandy and clayey) were used to culture earthworm, (Eudrilus eugeniae (Kinberg) in earthenware pots for ten weeks, under laboratory conditions. The aims of the research are to culture earthworms as replacement for fish meal, and to determine the best suitable soil medium for culturing and breeding of earthworms. Two sets of treatments were set up with the three soil samples; the experimental containing organic matter (cow dung) and the controls lacking organic matter. Watering was done every three days to keep the culture moistened. but not saturated. Results of the study showed that loamy soil had the highest number of earthworms harvested, followed by sandy and then clayey soil. Increase in number of harvested earthworms between the experimental and control groups differ significantly (P< O.05), with the experimental group having higher number of harvested earthworms. Loamy soil was the most favourable medium that enhanced the growth and survival of earthworms, when cultured under laboratory conditions, for fish meal replacement in aquaculture

Effects of soil types and enhanced nutrient levels on the productivity of earthworm (eudrilius eugeniae, kinberg)

The productivity, in terms of ability to reproduce, of the earthworm Eudrilius eugeniae (Kinberg), was studied in the laboratory under three (sandy, loamy and clayey) soil conditions with and without cow dung enrichment, in order to determine their individual suitability for the culture and breeding of the species. Ten earthworms of equal sizes were each introduced into two groups of twelve pots, each subdivided into three groups of four pots each, containing 9500g of ordinary sandy, loamy or clayey soils (served as control), and 300g cow dung enriched sandy, loamy and clayey soils (served as experimental). Experimental and control pots were moistened with 750cm3 of water every three days for ten weeks. Both sets of pots were assessed for total earthworm population, their weights and lengths. Percentage increases in earthworm population in the control soil media were 72.5%, 92.5% and 170% in clayey, sandy and loamy soils respectively. Experimental pots yielded 560%, 1700% and 3395% increments in earthworm population for clayey, sandy and loamy soils respectively. Population increments amongst the three soil media differed significantly (

Effect of Stocking Density on Production of Clarias Gariepinus (Tuegels) in Floating Bamboo Cages at Kubanni Reservior, Zaria, Nigeria

The African Catfish (Clarias gariepinus, Teugels) were reared at three different stocking densities in bamboo-net cages to evaluate the effects of stocking density on growth, survival rate and food conversion ratio. Three hundred (300) fish with a total weight of 1.8Kg were stocked at 25, 50 and 75 fish/ m3 cage with a mean weight of 5.6±0.23g, 5.9±0.23g and 6.3±0.23 g/m3 respectively. The growth trial lasted for 150 days (May 2009 to October 2009). Twenty percent (20%) of the total biomass of the fish in each cage was weighed monthly and the bulk weights were calculated. Mortalities were recorded monthly. The final mean weights (±S.E) of the fish stocked at densities of 25, 50 and 75 fish/m3 cage were 828.0±1.83g, 774.0±20.18g and 693.0±34.20g. The corresponding mean values of Specific Growth Rate were 3.33, 3.25 and 3.43. Temperatures ranged between 24.50C - 32.60C while salinity ranged between 24 - 95ppm. The Feed Conversion Ratio (FCR) was 4.99, 4.73, and 3.43, and cumulative survival rates were calculated as 99.84, 99.66 and 99.50% respectively. The results revealed that stocking density had a significant (P&gt;0.05) effect on growth and survival rates of Clarias gariepinus. Fish held at the highest stocking density exhibited the lowest growth and survival rate. Cages with 50fish/m3 stocking density had the best production with total final weight (38.67Kg) and profit index (3.27) compared to other treatments (P&gt;0.05).Keywords: Stocking density, bamboo-net cages, profit index, survival, growth, Clarias gariepinu

Comparative growth response of African catfish, Clarias gariepinus fingerlings fed with imported and local feeds

The comparative growth response of African catfish fingerlings (Clarias gariepinus) fed with three (3) local and three (3) imported feeds was studied in the Department of Biological Sciences, Ahmadu Bello University, Zaria between September and October, 2009 with the aim of establishing the best quality feed in terms of specific growth rate, total weight and percentage survival rate for a period of 8 weeks (56 days). One hundred and twenty (120) fingerlings of Clarias gariepinus and six commercial feeds with varying crude proteins namely Chivita, Aquaplus, Vital, Skrettings, Multifeeds and Coppens were used for the experiment. Some water quality parameters analyzed indicated temperature varied from 25.50 ~'C to 28.0 ~'C while pH and dissolved oxygen ranged from 6.6 to 7.2 and 6.3mg/l to 8.2mg/l respectively. The treatment shows significant difference in terms of mean weight gain, specific growth rates and survival rate. The lowest SGR was 0.31 and 0.89 the highest. Fish fed with Chivita and Coppens showed the best growth compared to other treatments

Acute toxicity of galex to Oreochromis niloticus (Trewavas) in Nigeria

The acute toxicity of galex (Metolachlor) to fingerlings of Orechromis niloticus (Trewavas) was determined in 96hour static bioassays. During the assays, opercular ventilation and tail fin movement rates of the fish were determined. Haematological parameters of the blood and histopathology of the gills were observed. The 96hours LC50 of galex to fingerlings of O. niloticus was observed to be 9.30mgL-1~c 1.04. Histopathology of gills of the fish exposed to l100mgL -1, 1200mgL and 13..00mg/L-1 showed a dose-dependent disruption of the architecture of the lamellae and atrophy which led to impairment in oxygen uptake. Other symptoms of toxicosis in exposed fish include haemorrhage of the gills and fins, blood shot eyes of the fish, copious production of mucus on the body and head, agitated swimming, eruption of the ventral side and spilling out of the digestive system of fish, air gulping and death

Preliminary evaluation of a new fishing pot trap in Lake Kainji, Nigeria

Based on personal working relationship with artisan fishers in the southern portion of Lake Kainji, North Western Nigeria, a new fishing pot trap made with polyvinyl chloride pipe material was designed, fabricated and its performance evaluated by comparison with the traditional Malian trap. The aim was to have a fishing pot trap that is long-lasting and be at least as effective as the Malian trap in fish catch. The results of the study revealed the advantages and limitations in the design and mode of operation of each of the trap type and recommended areas of improvement. Data collected on fish diversity, number and weight were subjected to descriptive statistics and Student’s t-test. The results showed that nineteen fish species belonging to ten families were caught. While the same species density index (SDI) of 0.84 was recorded for both traps, there was no significant difference (P>0.05) in the catch by number and weight of the two traps

Length-Weight Relationship and Condition Factor of Clarias anguillaris (Family: Claridae) in Kontagora Reservoir, Niger State, Nigeria

Length &ndash; weight relationship of Clarias anguillaris (Fam: Claridae) in Kontagora Reservoir, Niger State, Nigeria, was studied from January, 2007 - December, 2007. The fish species was obtained using a fleet of graded gill nets comprising of nine multi filament gill nets mesh sizes. The parameters a and b of the Length &ndash; weight relationship of the form W = aLb and Condition factor C.F. = W 100 / L3 are presented for the fish species. The mean monthly condition factor values were high during the rainy season than the dry season, and the b value obtained was 3.477. The b value indicates positive allometric relationship, with the weight of the fish increasing as the fish grow in length. The high mean monthly condition factor of the fish species indicating their well being, shows that Kontagora Reservoir has favourable environment for the survival and growth of the species.Keywords: Length &ndash; weight relationship, Condition factor, Clarias anguillaris, Kontagora ReservoirNigerian Journal of Basic and Applied Science (2011), 19(2): 299-30