Fish distribution in a small domestic water supply reservoir: a case study of Kangimi Reservoir, Kaduna, Nigeria

A study of the composition and distribution of fish populations in the inshore, surface and bottom water habitats of Kangimi Reservoir showed that the most abundant family was the Cichlidae followed in order of abundance by the familiesCyprinidae, Schilbeidae, Mormyridae, Mochokidae, Characidae, centropomidae and Bagridae. Though the overall composition of families caught inn the three habitats did not vary significantly (P>0.05) only family Cichlidae showed habitat preference: there was a preponderance of Cichlidae in the inshore water habitat (P<0.05). The families Bagridae and Centropomidae were caught only in the inshore and bottom water habitats while the other families were caught from all habitats and showed no habitat preference. The dominance of primary and secondary consumers indicates high fish production potential under adequate managemen

Predicting the fisheries potentials of inland reservoirs and lakes: a case study of Kubanni Reservoir, Ahmadu Bello University, Zaria

The depth, alkalinity, total dissolved solids and conductivity of Kubanni Reservoir were monitored biweekly between December 2003 and April 2004. The range values and their means were 0.8-4.64m, 42-67mg/l, 52-71mg/l and 104-142 mhos/cm; 2.8m, 42.6mg/l, 59.8mg/l and 119.6 mhos/cm respectively. Total Dissolved solids correlated significantly (P<0.05) with depth and conductivity while alkalinity correlated highly and significantly(P<0.05) with conductivity, total dissolved solids but negatively correlated with depth. The electrical conductivity was positively and highly correlated with depth while Morpho-Edaphic Index (MEI) which increased with depth decrease correlated positively with conductivity. Based on the average value of the MEI the potential fish catch of the reservoir was estimated to be 38kg/ha. This estimate was compared with other values obtained from other African reservoirs/lakes and management considerations under "private liability company" are proffere

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

Feed conversion, protein efficiency, digestibility and growth performance of Oreochromis niloticus fed Delonix regia seed meal

Oreochromis niloticus fingerlings (mean weight 5.27~c0.29g) were fed raw and boiled Delonix regia seed meals following standard procedures. The weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), net protein utilization (NPU) were determined as growth indices. Diet formulated with seed boiled for 80 minutes showed significantly (P<0.05) high values for the growth indices. Carcass nutrients composition were significantly (P<0.05) higher than in the control (raw) diet. Delonix regia seed meal when boiled has high potential of being utilized efficiently by O.niloticus. The implications of the respective index in fish metabolism are discusse

Some aspects of the physico-chemical parameters of Kontagora Dam, Niger State Nigeria

The seasonal variations in the physicochemical parameters were studied from January, 2007 to December 2007, in Kontagora Reservoir, Niger State, Nigeria. The physico- chemical parameters were determined bi-monthly , using the following methods , temperature using mercury thermometer in degree centigrade, transparency using Secchi-disc , Pye Unicam model 292 meter used for pH and electrical conductivity. Dissolved oxygen by modified Winklerazide method, water hardness and Phosphate- phosphorus by method of Lind (1979), total alkalinity by standard method described by Boyd(l979) , Nitrate- Nitrogen by Phenoldisulphonic acid method. The rainy season mean values for water temperature, depth, pH, Nitrate-Nitrogen, were significantly (P<0.05) higher than those for the dry season. However, for transparency, conductivity, dissolved oxygen, hardness, alkalinity, phosphate-phosphorus and total dissolved solid, the dry season mean values were higher than the rainy season mean value. As in most other Africa inland water bodies, there was seasonality in the physicochemical parameters variables. The torrential rains of the dam environment, the characteristics trade winds of the dry season, effect of deforestation, fertilizer application, herbicides, insecticide and other chemical factors might have contributed to the fluctuations of some of the physicochemical parameters detennined in the Reservoir

The use of Biological Index of Pollution (BIP) in assessing quality of rural water sources in Zaria, Nigeria

The biological index of pollution (BIP) which hinges on the responses of aquatic biota to pollution of water sources was used to assess the quality of some water sources in Zaria area, Nigeria. Water samples were collected from 15 stations comprising three open water sources (lakes) and twelve hand-dug wells on a monthly basis for a period of 24 months. Ten liters of the samples from wells were concentrated to 50 ml by filtering through 70 meshes per cm2 plankton net. Collections from the lakes was by means of dragging net over a 3 meter distance in the water. The water was also concentrated to 50 ml. Using the BIP of Horasawa as modified by Palmer, the water quality situation of the sources were classified into betasaprobic and alphasaprobic. Some of the water sources, especially in the rainy season, gradually shifted in quality from betasaprobism to alphasaprobism. The BIP method gave a satisfactory indication of the quality status of each water source especially when the results obtained were compared with the result of physico-chemical analysis of the water sources. However, unless the water sources contain both phytoplankton and zooplankton, which are key variables in the BIP computation, the index proved difficult to apply. Key Words: Rural Water Sources, Water Quality, Biological Index

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

Capture fisheries of Kontagora Reservoir, Niger State, Nigeria

A study of the capture fisheries of Kontagora Reservoir was carried out between January - December, 2007, using statistical frame and catch assessment survey methods. Five fish families comprising seven fish species were recorded. Hemichromis fasdatus, a cichlid was the most dominant species with mean value of 414.3 and 7715Kg in terms of number and weight respectively. Nineteen commercial fishermen were recorded, with the following fishing gears: gill net, cast nets, long lines, and Malian traps. The fishing craft included wooden canoe. The total mean catch of the fishermen were 4.40(1.36) kg/canoe or 167(52.64) fishes/canoe. The reservoir was productive in comparison 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 mesh size of 3” and establishment of community based cooperative scheme

Inventory survey of Nigeria inland waters and their fishery resources. Part 1. A preliminary checklist of inland water bodies in Nigeria with special reference to ponds, lakes, reservoirs and major rivers

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