Effect of salinity on growth and survival of Clarias gariepinus (Burchell, 1822): Clariidae fry

The effect of different salinity levels on the growth and survival of Clarais gariepinus fry was studied in indoor hatchery system for a period of three weeks. 1000 Clarias gariepinus fry of an average weight 0.37~c0.06g were stocked at 100 fry in five replicated 20 liters plastic bowls. Five salinity levels of 0.2, 0.4, 1.1, 2.1 and 4.2ppt were tested. The results indicated that significant difference P~.0.05 highest weight gain of 0.89~c0.05g was presented by fry in 0.2ppt medium. All fry raised in 4.2ppt died within 24 hours. No significant difference P~,0.05 in weight gain is presented in fry raised in 0.2ppt-2.1ppt. From this study, the weight gain decreases with increase in salinity. Also the survival rate decreases from 0.2ppt to 1.1ppt raised fry while the lowest significant difference P~.0.05 survivals were presented in fry raised in 2.1 and 4.2ppt. Based on these results and foregoing, salinity rate of 0.4ppt is favourable for growth and survival of C.gariepinus fr

Aquaculture potentials and investment opportunity in shrimps and prawns farming in Nigeria

Some aspects of the aquaculture potentials and investment opportunity in shrimps and prawn farming in Nigeria were overviewed. This paper presents the breeding pattern, spawner availability, culture water-type and properties, feeds and feeding regimes and other factors needed in practical shrimps and prawns culture. The culture systems, water management, larval management, stocking density, feeding strategies and diseases were fully discussed. The investment opportunity available as government plans to boost production of these resources from both artisanal and aquaculture sector was documented. Management strategies needed in practical practices of shrimps and prawns culture were enlisted. Effected efforts from the government were listed in this pape

Nutritive potentials and utilization of garden snail (Limicolaria aurora) meat meal in the diet of Clarias gariepinus fingerlings

The possibility of using garden snail (Limicolaria aurora) meat meal as a protein source in fish feeds was tested in Clarias gariepinus fingerlings. Five isonitrogenous (43% crude protein) diets in which garden snail meat meal was used to replace fish meal at 0%, (control diet), 25, 50, 75 and 100% inclusion levels were used for the study. The fish were fed ad-libitum for 8 weeks. Garden snail meat meal used had a crude protein content of 66.76% and ash content of 4.10%, while crude protein and ash content of fishmeal used were 72.46% and 18.22% dry weight, respectively. The lipid content of garden snail meat meal and fishmeal; 7.85% and 7.97%, respectively, was not significantly different (p0.05). The mean weight gain, relative growth and specific growth rates were highest in fish fed 25% garden snail meat meal diet. The best food conversion ratio (1.21) and protein efficiency ratio (3.69) were also recorded in fish fed 25% garden snail meat meal diet. Visceral somatic indices (2.71-17.24%) increased significantly (p0.05) with increase in the garden snail meat meal inclusion in the diets

Growth performance and nutrient composition of Bufo maculata (Linneaus) tadpole fed different practical diets as fish meal substitute

One thousand and one hundred (1,100) Bufo maculata tadpoles of weight range 0.03 -0.05 g (mean = 0.04 ± 0.008 g) and length range, 1.2 - 1.6 cm (mean = 1.4 ± 0.018 cm) were collected from the breedingtanks using scoop net and stocked into the outdoor concrete culture tanks coded according to the experimental diet at the rate of one hundred and twenty tadpoles of known weights and lengths per tanks and cultured for 84 days. The growth performances, feed utilization and nutrient composition of the tadpoles (B. maculata) fed three experimental diets namely live zooplankton alone (D1), 40% crude protein National Institute for Freshwater Fisheries Research (NIFFR) crumb diet alone (D2) and mixed diet (50% live zooplankton and 50% of dry 40% crude protein NIFFR crumb (D3) were studied. They were harvested after culture and processed into meal. The best mean weight gain (3.65 g/tadpole), specific growth rate (2.34%/day) and feed conversion ratio (2.05) were from tadpole fed mixed diets

Strategies for reducing hydrocarbon emissions in diesel low temperature combustion

Government legislation on particulate matter (PM) and oxides of nitrogen (NOX) emissions have become increasingly stringent over the past decades. Future projections have led to internal combustion (IC)engine developers exploring advanced combustion technologies which may replace or supplement current state of the art systems. Advanced combustion technologies such as Low Temperature Combustion (LTC) cover a broad series of mechanisms that seek to attain in-cylinder Equivalence ratio (f) - Temperature (T) combinations during combustion which lead to acceptable emissions of exhaust PM and NOX. These are generally achieved by a combination of EGR dilution and extended ignition delays for mixture preparation. Another common feature of LTC is the poor combustion efficiency due to severe requirements placed on mixture quality as lower temperatures and oxygen concentrations reduce local ignitability limits. Therefore, a significant amount of work on LTC is centred around understanding the spatial and temporal development of inadequately prepared mixtures during LTC. The investigations presented in this thesis are expected to contribute to this body of work as they are predicated on the hypothesis that current mixture preparation methods are insufficiently adapted to conditions present in LTC combustion modes. [Continues.

Haematological response of Heterobranchus longifilis fed varying dietary protein levels

Hematological effects of feeding varying dietary crude proteins levels to one hundred and fifty (150) H.longifilis fingerlings was examined on biweekly basis. The fingerlings of mean weights 1.26g plus or minus 0.24g were stocked in eight hapa nets (1mx1m) at 15 fingerlings per hapa. Four experimental diets with crude protein; 35%, 40%, 45% and 50% coded diet 1-4 respectively were fed to the fish for 8 weeks. The blood sample was taken and examined for packed cell volume (PCV) total protein (TP) Hemoglobin (Hb), Serum album, Erythrocyte count (RBC), while blood cell (WBC) mean corpuscle volume (MCV) and mean corpuscle hemoglobin, concentration (MCHC). There was an increase in the values of the hematological indices studied with increase in protein inclusion levels. A higher positive correlation with no significant difference (P greater than or equal to 0.05) exists between the treatments RBC, WBC, Hb and TP. The best RBC (2.10x10 super(6) count/l). WBC (7.65x10 super(4) count/l), PCV (35.4%) and Hb (5.79mg/l) were presented in fingerlings fed 40% crude protein followed by 45% crude protein. The dietary crude protein of 40% is recommended for H. longifilis for sound and healthy conditio

Length-weight relationship and condition factor of Clarias anguillaris from the wild and cultured in Nigeria

The correlation coefficient (R2) for Jos (cultured, Clarias anguillaris was 0.8367 while the coefficient of b was 3.1046. The correlation coefficient (R2) for Jos (wild) showed 0.7785 while the coefficient b was 3.4779. The correlation coefficient (R2) for Yola (wild) revealed 0.8637 and the coefficient of b was 2.4785. The results showed that there was correlation of length and weight in all the samples though Jos (cultured and wild) had positive allometric growth while Yola (wild) had negative allometric growth

Performance of Heterobranchus longifilis fingerlings fed maggot meal-based diets in miniflow through system

The growth response, nutrient utilization, cost benefits and haematological responses of two hundred and fifty (250) Heterobranchus longifilis fingerlings fed maggot meal based diets were evaluated for 70 days in mini flow through system. Twenty fingerlings were stocked in triplicate in fifteen mini flow through system of plastic tanks of fifty (50) litres capacity and coded MM1 - MM5 in relation to their diet name. Five isonitrogenous (40.0%) and caloric content (2017.S 2092.3kJ/100g) maggot meal based diets namely MM1 O%maggot meal, MM2 25% maggot meal, MM3 -50% maggot meal, MM4- 75% maggot meal and MM5- 100% maggot meal were used for the experiment. The higher the proportion of maggot in the meal, the higher the ether extract and crude fibre. No significant difference (p>0.05) existed between ash content of the experimental diets. Diet MM2 had the best growth performance and highest MGR with a significant difference (p0.05) existed between the growth parameters for diets MM1 MM3 and MM4 A positive correlation (r = 1.0) existed (p<0.05, 0.25) between the growth parameters for the different experimental diets. Highest correlation (r =0.9981) existed p<0.05 between MGR within the treatments. Highest Haematocrit (23%) Haemoglobin content (7.68g/dl) and whole blood clotting time (46 see) were recorded from H. longifilis fed MM5. Without any reservation, inclusion of maggot based meal diet is recommended as feed in the diet of H. longifilis to 75% replacement of fish meal for growth and better healthy condition so as to ensure sustainable aquaculture in Nigeria

Nutritive potentials and utilization of garden snail (Limicolaria aurora) meat meal in the diet of Clarias gariepinus fingerlings

The possibility of using garden snail (Limicolaria aurora) meat meal as a protein source in fish feeds was tested in Clarias gariepinus fingerlings. Five isonitrogenous (43% crude protein) diets in which garden snail meat meal was used to replace fish meal at 0%, (control diet), 25, 50, 75 and 100% inclusion levels were used for the study. The fish were fed ad-libitum for 8 weeks. Garden snail meat meal used had a crude protein content of 66.76% and ash content of 4.10%, while crude protein and ash content of fishmeal used were 72.46% and 18.22% dry weight, respectively. The lipid content of garden snail meat meal and fishmeal; 7.85% and 7.97%, respectively, was not significantly different (p0.05). The mean weight gain, relative growth and specific growth rates were highest in fish fed 25% garden snail meat meal diet. The best food conversion ratio (1.21) and protein efficiency ratio (3.69) were also recorded in fish fed 25% garden snail meat meal diet. Visceral somatic indices (2.71-17.24%) increased significantly (p0.05) with increase in the garden snail meat meal inclusion in the diets