African Journal of Fisheries Science

African Journal of Fisheries Science Vol. 2 (1), pp. 058-061, January, 2014. © International Scholars Journals

Full length Research paper

Ichthyofauna variety of Lake Asejire: natural implications

 Akinlade S. Temenu

Department of Wildlife and Fisheries, Faculty of Agriculture, University of Ibadan, Nigeria. E-mail: [email protected]

Accepted 29 December, 2013

Abstract

The natural diversity of most aquatic systems has witnessed various changes in stock diversity and abundance resulting from structural changes in habitat, food composition and uncontrolled exploitation. These have altered the ecology of the fish resources with the disappearance of some species and dominance of others. This study seeks to identify the ecological implication of the stock diversity and abundance in Lake Asejire. Lake Asejire is a 525 ha man-made lake on river Osun one of the major rivers that drain the western part of Nigeria. Fish samples were collected for a period of 24 months using gillnets of between 25 and 187.5 mm mesh sizes. Data obtained were analyzed using inferential statistics and descriptive analysis of means, frequencies and percentages. Seventeen families identified and grouped into trophic levels. Herbivores were 63.03 and 60.35%; carnivore 31.05 and 30.65% and omnivores were 5.91 and 8.99% by biomass in the first and second year respectively. The herbivores were dominated by the cichlids, heterotis and cyprinids; carnivores by bagrids, characids, channids and Lates while mormyrids, synodonts and clarids constitute the omnivores. Seasons had no effect on the population and number of the carnivores. The carnivore to herbivore ratio (F/C) was 1.33 and 0.9 by number and 1.7 and 1.33 by biomass; this is of concern as this could pose a threat to ecological balance. It is recommended among others that fishing pressure should be increased on carnivores and more herbivores be injected to the environment to prevent the collapse of the fisheries.

Key words: Fishing pressure, trophic levels, diversity, ecological balance, lake.

African Journal of Fisheries Science Vol. 2 (1), pp. 052-057, January, 2014. © International Scholars Journals

Full Length Research Paper

The outcome of cyclic feed scarcity on growth and economic limit of commercial feed-based in-door grow-out of Clarias gariepinus (Burchell, 1822)

Ephiede J Adebisi, Adetarami Dudusola and Akinlade S. Temenu

Department of Wildlife and Fisheries, Faculty of Agriculture, University of Ibadan, Nigeria. E-mail: [email protected]

Accepted 02 December 2013

Abstract 

Growth, feed utilization, and economic limit of commercial pelleted feed use were compared between daily-fed and feed deprived groups of Clarias gariepinus (Burchell, 1822) raised under low density culture. Groups of C. gariepinus were fed daily (Treatment 1) or on alternate days (Treatment 2) for 5½ months, with 45% crude protein commercial pellets. Feeding was at a rate of 6% body weight per day which was considered satiation feeding. Cost and revenue were determined on the basis of feed cost and revenue from fish sales respectively. Treatment 1 yielded profits up to a mean weight of 64±8 g at feed conversion ratio 1.0±0.08 and 4.71% loss at mean weight of 105±10 g and feed conversion ratio (FCR) 2.1±0.7. Treatment 2 was profitable up to harvest mean weight of 264±10 g. Feed conversion ratio, mean weight, and total weight, were significantly higher in Treatment 1 (p<0.05). Cost-benefit ratio and percentage profit were significantly higher in Treatment 2 (p<0.0001). Thus the economic limits were 2 months at mean weight of 105±10 g; and 5 months at mean weight 264±10 g; in Treatments 1 and 2 respectively. The skip-a-day feeding strategy adopted in Treatment 2 was effective in extending the economic limit of conventional feeding using commercial pelleted feed in low density commercial catfish culture. The limits established in this study could serve as an advisory to farmers on the appropriate time to switch from the expensive commercial pelleted feeds usually fed at the early stage of grow-out to farm-made feeds.

Key words: Clarias gariepinus, economic limit, low density, feed deprivation, satiation feeding, growth, feed utilization.

African Journal of Fisheries Science Vol. 1 (7), pp. 045-051, December, 2013. © International Scholars Journals

Full Length Research Paper

Small-holder aquaculture and Water bodies Contribution to poverty mitigation and enhancing household food security in Zambia

Jacquline Tembo, Sithole Hubber and Phiri H. Milner

Department of Aquaculture and Fisheries Management, School of Agricultural Sciences, University of Zambia, Lusaka, Zambia. E-mail: [email protected]

Accepted 26 November, 2013

Abstract 

A study was conducted between January and May 2011, through administration of questionnaires and personal interviews in 6 of the 10 provinces of Zambia (namely: Lusaka, Eastern, Central, North Western, Copperbelt, and Southern) in order to assess the contribution of small water bodies (SWBs) and small-holder aquaculture towards poverty alleviation and enhancing household food security. Using simple random sampling method, a total of 120 respondents were selected. Results indicated that, a total of 1,082 SWBs were constructed throughout the country covering a total area of 5,410 ha. Most of them were constructed for irrigation purposes and as sources of drinking water for livestock. At the same time, aquaculture adoption at household and intra household levels had increased by 4.7% in all the districts over the years. There were more than 11,327 small-holder farmers who owned 21,658 ponds, covering 578.86 ha of land. There was also a 10% increase in number of learning institutions and the hospitality industries that had adopted aquaculture activities either for recreational or learning purposes. Existing statistics indicated that, there were 11,327 small-holder farmers who owned 21,658 ponds, covering 578.86 ha of land with an annual fish production of 3,985.16 metric tonnes, while that from SWBs stood at 2,705 metric tons. It was however noted that, the majority of these farmers (65%) produced less than 0.5 tons of fish per hectare/year, which was considered to be very low. However, fish production from SWBs remained almost unchanged because extension support had remained very inadequate and the designed programme to enhance productivity in community small-water bodies was not being implemented. Most of the fish harvested comprised mainly of: Oreochromis andersonii, Oreochromis macrochir, and Tilapia rendalli, which were readily acceptable to the consumers.The study also revealed that, adoption of small-holder aquaculture helped in poverty alleviation, improved rural household food security and better nutritional status compared to non-fish farming families. Most of the small-holder farmers cultivated various agricultural crops through irrigation and were also involved in livestock rearing, from which extra income was realized.

Key words: Contribution, small-water bodies, small-holder aquaculture, poverty alleviation, food security, Zambia.

African Journal of Fisheries Science Vol. 1 (7), pp. 042-044, December, 2013. © International Scholars Journals 

Full Length Research Paper

The contrast between total cholesterol and cholesterol type of cultured rainbow (Oncorhynchus mykiss, Walbaum, 1972) and brook trouts (Salvelinus fontinalis, Mitchill, 1815) cultivated in the same water condition

Sergio D. Hasan, Arık Halit and Kazım Ozcan

Department of Wildlife and Fisheries, Faculty of Agriculture, Dicle University, Diyarbakır, Turkey. Email:[email protected]

Accepted 02 November, 2013

Abstract 

The aim of this study was to compare serum total cholesterol and cholesterol types of cultured rainbow trout (CRT) (Oncorhynchus mykiss) and cultured brook trout (CBT) (Salvelinus fontinalis) cultivated under the same water conditions. Fishes used in the research were randomly captured from pools and five pieces (five replication) were used for each group. The average weight of fish is 80 g for CRT and is 120 g for CBT. CRT and CBT have been fed with feed with 45 to 50%crude protein twice a day. The levels of serum samples excluding high density lipoproteins (HDL) obtained from the CBT were found to be higher (p<0.05) than that of CRT. Finally, higher serum samples in CBT could have resulted from difference of growth and size, species, age, the cycle of sexual maturity of fish.

Key words: Rainbow trout, brook trout, total cholesterol, high density lipoproteins (HDL), low-density lipoproteins (LDL), very-low-density lipoprotein (VLDL).

African Journal of Fisheries Science Vol. 1 (6), pp. 034-041, November, 2013. © International Scholars Journals

Full Length Research Paper

Fish feeding routine in Anwai stream ichthyofauna, Niger-Delta

Ephiede J Adebisi, Adetarami Dudusola and Akinlade S. Temenu

Department of Wildlife and Fisheries, Faculty of Agriculture, University of Ibadan, Nigeria. Email: [email protected]

Accepted 31 October, 2013

Abstract 

The food and feeding habits of some fish fauna in Anwai stream were investigated. Fish samples (160 individual fish in 19 species) were collected using combination of traps, gill nets of various mesh sizes and baited hooks and lines in the three zones (upper, middle and lower reaches) of the stream. Stomach content analysis was carried out using frequency of occurrence, numerical analysis and volumetric analysis. It was observed that Hemichromis Fasciatus competed with fish species of commercial importance viz Tilapia zilli, Christinus guentheri and Oreochromis niloticus for major food items (100 F% of blue green algae, green algae and diatom). Feeding intensity (absolute importance index) of Hemichromini bimasculatus (700) and O. niloticus (801) remain relatively higher than that of the other fish species during the study.

Key words: Stomach content analysis, frequency of occurrence, absolute importance index, Anwai stream.

African Journal of Fisheries Science Vol. 1 (6), pp. 028-033, November, 2013. © International Scholars Journals

Full Length Research Paper

Sperm Quality and reproductive performance of male Clarias Gariepinus induced with synthetic hormones (Ovatide and Ovaprim)

Ephiede J Adebisi, Adetarami Dudusola and Akinlade S. Temenu

Department of Wildlife and Fisheries, Faculty of Agriculture, University of Ibadan, Nigeria. Email:[email protected]

Accepted 07 October, 2013

Abstract 

Food, especially food protein source is highly essential for healthy living, therefore, this study was aimed at boosting fish seed production and it compared the effectiveness of two different synthetic hormones: Ovaprim and Ovatide on sperm quality and reproductive performance of male Clarias gariepinus and the resulting effects on percentage fertilization, hatchability, and survival. The study was made up of three experimental groups. The first group comprising four males was injected with 0.3 ml/kg of ovatide hormone, the second group with four males was injected with 0.3 ml/kg of ovaprim hormone; and the third group, the control group with four males was not given hormones. Sperm motility duration was higher in males induced with the synthetic hormones (29.5 and 25.5 s respectively) which were significantly different (P < 0.05) from the control (18.5 s). Motility percentage was observed to be higher too in the groups treated with the hormones and was different significantly (P < 0.05) from the control. Percentage egg fertilization was similar for the groups induced with the hormones (94.4 and 87.7% respectively) while the control (63.8%) differed significantly from them. Percentage hatchability was highest in eggs fertilized with milt from ovaprim induced males (66.3%) which was significantly higher than those of Ovatide induced males (59.7%) and the Control (14.4%). Milt volume was highest in ovatide induced males (1.1 ml) and was significantly different from ovaprim induced males (0.60) and the control (0.25). Survival rate was the same for all the treatment. The hormones gave similar results except for the milt volume. Treatment with the hormones yielded better result when compared to the control, it could be inferred therefore that, the use of synthetic hormones is better in reproduction of C. gariepinus in order to boost productivity thereby ensuring abundant food protein production.

Key words: Spermiation, reproductive performance, ovatide, ovaprim, male Clarias gariepinus