Potential for the development of aquaculture in Africa

Aquaculture production in Africa has remained low despite the huge potential that exists on the continent. In order for this potential to be realized, it is necessary to refocus the direction of aquaculture development. This paper concludes that for further growth to occur it is necessary to: (i) widen the range of production systems; (ii) increase production intensities and efficiencies; (iii) develop management technologies for indigenous species that target local niche markets; (iv) put more emphasis on marketing and processing of high value products; (v) promote policy research on how aquaculture production can respond to changing macroeconomic policies; and (vi) accelerate the disengagement of government from activities that can best be done by the private sector

Aquaculture research: technology transfer for rural development in Nigeria

Conventional aquaculture has been promoted in Nigeria for the past five decades with minimal impact on rural communities: from the findings of Maclearen (1949) where he popularized the use of culturable fish predators Lutjanus sp; Pomades sp; Tarpon adanticus; Chrysichthys nigrodigitatus in earthen ponds near Onikan-Lagos, Nigeria; to the finding of Zwilling, 1963, who reported common carp, Cyprinus carpio propagation and culture in Panyan Fish Farm, near Jos; to the findings of FAO, 1965, when the potential culture of marine mullets culture in brackish water ponds in Buguma, Rivers State was presented. The work of other researchers Sivalingam, (1970; 1973), Ezenwa (1976), development officers and extension officers contributed to the development of aquaculture in few rural areas of the country and informed on public and private owned fish farm infrastructures. Despite a moderate long history of aquaculture research and development in Nigeria, an annual production level of 25,000 metric tons was recorded in 1999. This situation calls for a more sustainable approach for a stronger link between aquaculture research and technology transfer for the development of rural communities of Nigeria. This paper therefore examines some of the issues involved in the continuous flow of the new aquaculture technology in the improvement of fish protein output, standard of living of rural farmers and prevention of urban migration by the yout

Fish sorting assessments of Clarias gariepinus fingerlings raised in fish tanks

Fish sorting assessments of Clarias gariepinus fingerlings stocked and raised in fish tanks were undertaken for a 6-month culture period: Sorting was undertaken from the first, second, and third months of stocking the fish fingerlings while the control was not sorted at all. The sorting assessments revealed that the twice sorting of fish fingerlings stocked with a Marginal Rate of Return (MRR) of 3.44 was significantly different (p>0.05) from those sorted once with MRR of 0.912, and three times with MRR of 2.65 respectively, thus making twice sorting most advisable for fish farmers utilizing Clarias gariepinus fingerlings for tank aquacultur

Melatonin and Vitamin C modulate cholinergic neurotransmission and oxidative stress in scopolamine-induced rat model of memory impairment

Background: Cognitive dysfunction which characterizes dementia is reportedly caused by multiple factors including oxidant-antioxidant imbalance, inflammation, alteration in synaptic neurotransmission. Despite the arrays of drugs available in managing dementia, it appears no single drug can effectively treat dementia. Since it is multifactorial, combining potential drugs may provide neuroprotective impact. As such, this study investigated the neuroprotective effects of melatonin and vitamin C on scopolamine model of cognitive impairment in rats and the possible mechanism of action. Methods: Thirty male Wistar rats were divided to receive either normal saline (5 ml/kg, p.o), scopolamine (1 mg/kg, i.p.), donepezil (2 mg/kg, p.o), melatonin (10 mg/kg, p.o), vitamin C (100 mg/kg. p.o) or melatonin plus vitamin C. Cognitive impairment was induced by daily injection of scopolamine (1 mg/kg, i.p.), after which different treatment regimen were administered for 15 days. Spatial memory was assessed using Morris Water Maze and modified light and dark box. The brain was processed for malondialdehyde (MDA), reduced glutathione (GSH) and acetylcholinesterase (AchE) activity. Results: Scopolamine-treated rats with no intervention showed impaired learning and memory as depicted by a significant (p<0.05) increase in escape latency, reduction in the frequency of visit to the escape aperture, increased MDA, decreased GSH and elevated acetylcholinesterase activity when compared to other groups. Interventions with melatonin or/and vitamin C reversed these responses respectively. The melatonin plus vitamin C treated group compared favorably with donepezil (reference group). Conclusion: Melatonin and vitamin C show neuroprotective effect in attenuating cognitive impairment in scopolamine-induced model by modulating oxidative stress pathway and enhancing cholinergic neurotransmission. Keywords: Dementia, Melatonin, Vitamin C, Memory, Scopolamine

Culture trial of (Peneaus) Penaeus monodon in concrete tank

Culture trial of the Tiger Shrimp (Peneaus monodon) was carried out in one of the grow-out concrete tanks at Nigerian Institute for Oceanography and Marine Research, Victoria Island, Lagos. A total of 264 post larvae of P. monodon (PL 30) produced at the Institute’s shrimp hatchery complex were used for the experiment which lasted for 157 days. Coppens Catco feed of 0.8 - 1.2mm size was used to feed the post larvae throughout the duration of the experiment. The results showed that the shrimps grew from an initial mean body weight of 1.763g at stocking to 19.538g at the end of the experiment. The daily growth rate was 0.113g/day while specific growth rate was 1.532 %. Food Conversion Ratio (FCR) was 3.362 while survival rate was 90%. The study has shown that P. monodon can be successfully cultured in concrete tanks. However further studies aimed at improving growth rate will be undertaken

Design and construction of a shrimp hatchery for the breeding of the black tiger shrimp Penaeus monodon

A shrimp hatchery for the breeding of the black tiger shrimp, Penaeus monodon was constructed by the Nigeria Institute for Oceanography and Marine Research in 2008 by the reconstruction of an existing old shrimp hatchery. The new shrimp hatchery comprises of the following: water treatment, water storage, broodstock maturation, spawning/incubation, nursery and micro-algae units. The design included the construction of a concrete sump for the collection and treatment of wastewater before disposal, in addition to an aeration unit equipped with root blower for adequate supply of dissolved oxygen. The reconstructed NIOMR shrimp hatchery has been successfully used for the production of post larvae, which are presently being reared to adult shrimp in concrete tanks. The successful completion of the shrimp hatchery and breeding of P. monodon has confirmed that the species can be spawned and reared to adult size in Nigeria for local and export markets

Effect of season on controlled propagation of the african catfish, Clarias gariepinus (Burchell 1822)

In IDL-993