Practical suggestions for the commercialisation of fishery production in Ondo State

The paper examines the fisheries resources and activities in Ondo State, Nigeria. As a result of the geographical advantage via location along the Atlantic coast the potentials and constraints of coastal artisanal fisheries in Ondo State are assessed. Practical suggestions and approaches for a successful commercialisation of fishery production are given. These include: (a) Identification of useful and reliable fisheries institutions, (b) Inauguration establishment and coordination of a fishery development agency, (c) establishment of aquaculture technology centres (ATC), (d) provision of fishery development fund, (e) Standardisation of fishery consultancy units, et

Gut contents and feeding pattern of Macrobrachium vollenhovenii (Herklots, 1857) and Caridina africana (Kingsley, 1882) at Asejire Lake and Erin-Ijesa waterfalls, South Western Nigeria

A study with intent towards acculturation was carried out on the gut conients and feeding patterns of Macrobrachium vollenhovenii and Caridina africana occurring at Asejire lake and Erin-Ijesa Waterfalls respectively for two years using numerical abundance and frequency of occurrence methods of analysis. There was a strong correlation (p<0.05) between prawn abundance and food availability, The gut content analysis of M. vollenhovenii revealed that juveniles were predominantly zooplanktivorous, feeding on copepods and rotifers while the adults were omnivorous, utilizing a wider variety of animal foods than plant materials. This changing of diets and patterns as the species advances in age has an implication for its culture potentials. Stomach fullness index was high during the wet season which coincided with high abundance of prawns, C. africana fed mainly on diatoms, zooplankton and other micro-phytoplankton, thus an onmivore with herbivorous tendency. The availability of both species in fresh water bodies and their foods revealed that both species can be cultured in earthen ponds since their unspecialized flexible dietary habit is an optimal strategy for sustained productivity

Biological assessment of Oreochromis niloticus (Pisces: Cichlidae; Linne, 1958) in a tropical floodplain river

Biological assessment of Oreochromis niloticus was conducted monthly between January, 2004 and December, 2006 in 3 zones [(Zone I: upper Cross River (savanna wetlands) Zone II: middle Cross River(savanna/forest wetlands) and Zone III: lower Cross River (forest wetlands)] along 200 km length of the inland wetlands of Cross River, Nigeria. Major items in the diet of O. niloticus were algae and plant 38and 20.4% (Zone I), 21.7 and 18.0% (Zone II), 20.2 and 26.9% (Zone III), respectively. Diet breadth ranged from 0.820 - 0.913. Food richness and Gut Repletion Index were 12 and 100%, respectively. Sex ratio was 1: 1 (Zone1), 1:0.78 (Zone II) and 1: 0.89 (Zone III). Mean allometric coefficients (b) of the lengthweight relationship were 2.194 ± 0.215 (Zone I), 2.935 ± 0.333 (Zone II) and 3.03 ± 0.202 (Zone III).Fecundity varied from 70 eggs for fish (total length (TL) = 11.00cm and weight (W) = 37.9 g) to 502 eggs (TL = 25.8cm and W = 198.8g) in Zone I, 60 eggs (TL = 13.3cm and W = 19.8g) to 709 egg (TL = 26.5, W= 317.0) in Zone II and 110 eggs (TL = 13.7cm, W = 24.0g) to 811 eggs (TL = 22.8cm, W = 278.8g) in Zone III. Relationship exists between fecundity and body size. Mean condition index ranged from 0.770 ± 0.128 minimum for males at Zone I to 1.188 ± 0.157 maximum also for males at Zone III. Therefore, male O. niloticus were in better condition than females and the forest wetlands of Cross River (Zone III) offered more favourable living conditions for the species than the savanna wetlands (Zone I and II)

The Food Habits of Ctenopoma pethereci, Gunther (Pisces: Anabantidae) in River Oluwa, Ondo State, Nigeria

The natural foods of Ctenopoma pethereci from River Oluwa in Ondo State, South-west Nigeria, were urrence and points methods of analysis. The quantity of food in the full stomach constituted 0.83% of the body weight while food in the intestine formed 1.54%, thus, giving the quantity of food in the entire gut as 2.37% of the body weight. There was little or no qualitative difference in the food items found in the stomachs and intestines. The food items encountered in the gut covered a wide spectrum, and the species is shown to utilize a wider variety of plant materials than animals. The dominant plant source included diatoms, blue-green algae, green algae and higher plants, while the range of animals included rotifers, copepods and insects. Organic detritus also formed a substantial portion of its food which amounted to 98.94%. The study revealed that C. pethereci is an omnivore with herbivorous tendency in River Oluwa

Whole rocky fresh water prawns, Caridina africana as replacement for fish meal in diets for African catfish (Clarias gariepinus)

Specimens of Caridina africana were oven dried at 110~'C for 24 hours and refrigerated at 200~'C prior to proximate analysis. Whole rocky freshwater prawn meal (WRFWPM) was evaluated as a dietary replacement for fish meal in the diet of C. gariepinus fingerlings. The diets were fed to triplicate groups of C. gariepinus fingerlings (10.6 ~c 0.08g) reared in concrete tanks, to assess the effects of its partial or complete replacement with fish meal for 90 days. The diets comprised a control which contained fish meal as a protein source; 0% and four others on weight basis at 25%, 50%, 75% and 100% in which fish meal was progressively substituted with WRFWPM. The crude protein content was 40% and fed at 4% body weight of the fish per day. Results shows that the daily body weight gain, feed conversion ratio, protein efficiency ratio and protein productive values were highest in diet with 50% replacement, closely followed by diet with 25% replacement. All parameters were significantly different for all diets (p<0.05). Higher dietary inclusion WRFWPM of 75% and 100% led to decrease in growth performance and nutrient utilization of C. gariepinus fingerlings. The cost WRFWPM was significantly lower than that of fish meal. Though the economic viability of C. africana is yet to be evaluated due to its tiny size; its substitution as a fish meal replacer in the diet of C. gariepinus is considered profitable

WATER QUALITY, FISH DIVERSITY AND CATCH ASSESSMENT OF IKERE GORGE OYO STATE, NIGERIA

Study of the physico-chemical parameters of Ikere gorge is one of the recently constructed man-made lake in Oyo state, Nigeria. The need to assess the fish diversity, water quality and catch assessment of this new water body was necessary. Data on fish species were collected on monthly basis using multi-stage gillnet sampling techniques for eighteen months. Four sampling stations were randomly selected from the entire gorge. In each sampling station (fishing villages) were randomly selected for the investigation of the fish composition and abundance. A variety of sampling methods were used at each site in order to reach every fish species. At the river channel and the floodplain sites, traps, cast nets (2.55cm mesh), seine nets (25.5x2m, cm mesh), monofilament nylon gillnets (15.55 cm mesh), and hook and line were employed. Effort were made in order to catch fish species in large abundance. Some sampled fish (dead) were collected and placed in cool boxes and examined within 18h of capture, others were preserved in 15% formalin and stored for later examination. Samples of catches from the commercial fishermen was in addition examined and assessed. A total of 5,736 fish specimens were caught during the study period. These were identified and classified into 34 species belonging to 13 families, and arranged according to Greenwood et al (1966). The percentage species composition of the harvest by numbers and weight for all fish species that contributed more than 1% in all the stations combine were computed. Data fish composition and abundance were collected. From field and Laboratory evaluation, Bagridae (25.1%), Cichlidae (37.1%) and Mormyridae (14.5%) were most abundant families contributing 76.7% by number and 75% by weight of the total catch followed by Characidae (9.6%), Cyprinidae (7%) and Centropomidae (3%) constituting (19.6%) by number and 8.7% by weight. Others; Schilbedae (1.1%) Clarridae (0.8%), Hepsetidae (0.7%0, Mochokidae (0.6%), Channidae (0.5%), Icthyoboridae (0.2%) and Malapteruridae (0.1%) were least represented (4% by number and 16.5% by weight of total catch). Study of the physico-chemical parameters such as dissolved oxygen ranged from 2.2 to 9.1mg/l; temperature, 24.2 to 300C; alkalinity, 94 to 118ppm; conductivity, 81 to 86.7ohms/cm; pH, 6.04-8.62; transparency 50cm to 3.9m; nitrate, 258.15-532.6mg/l; total dissolved solids, 0.142-782mg/l; depth, 25-33.60m; pH and water temperature serve as variables since the fluctuation of one affects the values of others. The water quality parameters were favourable for fish production. The gillnet fisheries indicated that different mesh sizes of experimental gillnets were sensitive to different fish species. 78.4mm, 112mm, 67.2mm mesh sizes were efficient in catching C. nigrodigitatus L. niloticus and the cichlids respectively. Other gears used were cast net, traps, bamboo stems, spears and gura net. The study has shown that station iv was the most suitable habitat for fish in Ikere gorge. Water level and temperature were observed to guarantee high fish yield in the gorge.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp

Heavy metals contamination of Chrysichthys nigrodigitatus and Lates niloticus in Ikere Gorge, Oyo state, Nigeria

This study investigates the presence of heavy metal contamination of Chrysichthys nigrodigitatus and Lates niloticus. Adult C. nigrodigitatus and L. niloticus were obtained from fishermen in Ikere Gorge, Oyo state, Nigeria. Water samples were also collected during the wet and dry seasons of the year in the same locality. The presence of five metals were analyzed in both fish and water. Iron, copper, zinc, lead and manganese were investigated by atomic absorption spectrosocopy (AAS) in two separate experiments. In each case, four tissues; gills, bone, intestine and muscle were compared with the level of metals in the water. Lower concentrations of metals were recorded in water than in fish. Lower concentration of the metals found in fish and water was less than that recommended by the World Health Organisation (WHO) guideline for maximum concentration recorded in the tissue of the two samples. Iron was found to be dominant in the intestine of C. nigrodigitatus, while manganese was found to be highest in the bone of L. niloticus, copper recorded the least of all the metals. There is significant difference (P &lt; 0.05) in heavy metals concentration in the gill of C. niloticus and water, as well as the concentration in the intestine of L. niloticus and water. It was concluded that though the heavy metals of interest were present in measurable quantities, they were still within safe limits for consumption.Key words: Heavy metals, fish, gorge, contamination

Effects of diesel-oil spillage of fresh, brackish and marine waters on polyvinyl-alcohol (PVA) synthetic fishing twine

The effects of diesel-oil spillage of fresh (0.4ppt), brackish (25ppt) and marine (37ppt) waters on elongation (cm) and breaking load (kgf) of artisanal PVA synthetic twine of varied diameter (4mm, 6mm, 8mm and 10mm) soaked for 16 weeks was studied. Chemical (solubility) test was carried out to identify the experimental twine as PVA among other synthetic twines. The elongation (cm) and breaking load (kgt) of PVA twine diameters were tested by tensile-strength gauge machine (0-200kg) and was carried out in unpolluted (control) and polluted states (spillage level) at 0%, 20%, 40%, 60%, 80% and 100% diesel-oil concentrations of different water salinity. Factorial statistics was used to analyze the treatments; twine (at four levels), water salinity (at three levels) and concentrations (at six levels). This implies 4 by 3 by 6, replicated in four places (288 treatments). Results indicated that elongation (cm) and breaking load (kg) of the specimens were significantly (P<0.05) influenced by twine thickness. Twine l0mm soaked in 3.0 litres of unpolluted freshwater had significant (p<0.5) correlation coefficient r,0.927 and lowest r- value of 0.499 was obtained in twine 4mm soaked in 100% diesel-oil concentration. Significant (P <0.05) relationships were observed between the correlation coefficient r = 0.531-0.927 for unpolluted and r = 0.499-0.592 for polluted tests. The study revealed that diesel-oil spillage had negative effects on the quality of twines. The thicker the PVA twine diameters (10, 8, 6 and 4mm) at lowered (0%, 20%, 40%,60%,80% & 100%) diesel-oil spillage of fresh (0.4ppt), Brackish (25ppt) and Marine (37ppt) waters respectively, the higher the significant (P<0.05) elongation (cm) and breaking load (kgt) were evaluated in most cases

Biological assessment of Oreochromis niloticus (Pisces: Cichlidae; Linne, 1958) in a tropical floodplain river

Biological assessment o

Comparative Economic Analyses of Production Efficiency of Fadama II Catfish Beneficiaries with Non- Beneficiaries, Ogun State, Nigeria

This study compared the production efficiencies of Fadama II catfish farmers with non-beneficiaries in Ogun State. Stochastic Frontier Analysis and difference of mean statistics were used to analyze the primary data collected from two hundred and seventy (270) respondents among the 10 the Fadama participating Local Government Areas. The Maximum Likelihood Estimates (MLE) for the production function revealed that fertilizer (X1), quantity of feed (X3) and pond size (X7) at  (p&lt;0.01) determined the output of the beneficiaries and quantity of feed (X3) (p&lt;0.05), fingerlings (X5)and pond size(X7)  at (p&lt;0.01) also have positive and significant effect on the output of the non-beneficiaries. The production  inefficiency analysis  revealed that farm efficiency would increase with increase in benefits status and extension contact(p&lt;0.01). The MLE for cost function revealed that  lime(X1) and fingerlings(X5)  decreased the production cost, quantity of feed(X3) (p&lt;0.1) increased the cost among the beneficiaries. while quantity of feed(X3), labour(X4)  and pond size (X7) on the other hand increased the production cost among the non-beneficiaries.  The cost inefficiency analysis further revealed that farming experience  decreased the cost efficiency but increased the economic efficiency and the  t-test showed significant difference (p&lt;0.01) between the technical efficiencies of both sets of respondents. The beneficiaries are more efficient in terms of their technical, allocative and economic efficiencies than their non-beneficiary counterparts. The study recommends the expansion of the project scope to all the non-benefitting communities, provision of conducive environment for the establishment of ponds in all parts of the country to encourage more citizens to get into fish farming business and by extension, alleviate poverty status and un-employment in the state and country at large. The link between the Village Extension Agents (VEAs), Fadama Facilitators and the Fadama fish farmers should be strengthened through continual training and capacity building initiatives, if the objective of sustainably increasing Fadama farmers’ income is to be achieved. Keywords: National Fadama Development Project II (NFDPII), Beneficiaries, Non-beneficiaries,  economic analysis, Production  efficiency , catfish production, Ogun state, Nigeria