Prospects and problems of rice-fish culture in Nigeria

This paper examines fish demand and supply and looks at on-going research works in rice-cum-fish culture in Nigeria. It examines all the pre-requisites for adopting this farming system. Economic and Financial analysis were made using experimental plots at two ecological zones of Nigeria. This farming system, which has reached advanced stage in most of Asian countries, could well be practiced in Nigeria to assist farmers to harvest both protein (from fish) and carbohydrate from rice and thereby to improve their standards of live

An appraisal of the efficiency of fish marketing system in Lake Chad basin

Fish products from the Chad Basin Lake play important role in meeting fish protein needs of Nigeria: they contribute not less than 25% of the total domestic fish supply and are significant in determining the availability of processed products and reduction of post-harvest losses. Processors, marketers and consumers are the major actors in appraising a marketing system. The results show that most sellers (4-7.5%) are within the age range of 30-39 years. Desires for more earnings led the markets to diversify their business activities to food stuff trading (37.5%), dried meat/livestock sales (37.5%), farming (12.5%), and transportation (12.5%). 65% of traders dispose off their products mostly in the mornings and evenings, 70% of the products are sold smoked while 50% of products are sold to individual consumers. Lake Chad fish products have a long distribution chain. There is also a high degree of buyers and sellers concentration in the primary fish markets and secondary (urban) markets. The products have a vertical regional movement with southern traders (82.5%) dominating the business, thus making the products popular all over Nigeria. Product differentiation with imperfect pricing policy is common occurrence. Lake Chad fish marketing system has distortions that impede its efficiency, recommendations are made on how to ensure a better efficiency of the system

Integrating cultural, economic and environmental requirements for fish production in Borno State

The study examines the integration of cultural, economic and environmental requirements for fish production in Borno State, Nigeria. A reconnaissance survey was conducted transferring some selected Local Government Areas. 60 questionnaires were administered in the six Local Governments representing Southern Borno State with Biu and Shani, central Borno with Konduga & Jere and Northern Borno with Gubia and Kukawa respectively. There is no cultural constraint to fish production but about 63% prefers to invest in other farming activities than in fish farming. 33% are not aware that fish can be cultured apart from getting it from the wild. 35% have the impression that fish farming ventures can be handled by government only. The economic earnings for fish production are high especially in some parts of Northern Borno, but the Local market potentials throughout the state are great. Nigeria has suitable soil for ponds apart from few locations at the central and Northern Borno that are made by sandy soil. Numerous perennial and seasonal rivers, streams, lakes, pools and flood plains adequate for fish culture especially in Southern Borno exist. The mean annual rainfall can result in some water storage in ponds. In areas where the annual precipitation is less than 550mm, exist few flow boreholes with potentials for fish production. The temperature regime may support growth and survival of fish even during the hottest months of the year (March, April and May). With the understanding and manipulation of these requirements, fish production in Nigeria can be greatly enhanced

Marketing and distribution of fish from Lake Chad

This study provides information on fish quantities, economic data and flows of Doro fish market near Baga, Nigeria, known as the major fish market on the Nigeria section of the Lake Chad

Spawning seasons of Rasbora tawarensis (Pisces: Cyprinidae) in Lake Laut Tawar, Aceh Province, Indonesia

Rasbora tawarensis is an endemic freshwater fish in Lake Laut Tawar, Aceh Province, Indonesia. Unfortunately, its status is regarded a critical endangered with populations decreasing in recent years. To date no information on the spawning activities of the fish are available. Therefore, this study provides a contribution to the. knowledge on reproductive biology of R. tawarensis especially on spawning seasons as well as basic information for conservation of the species. Monthly sampling was conducted from April 2008 to March 2009 by using selective gillnets. The gonadosomatic index, size composition and sex ratio were assessed. The gonadal development was evaluated based on macroscopic and microscopic examinations of the gonads. The gonadosomatic index (GSI) varied between 6.65 to 18.16 in female and 4.94 to 8.56 for male. GSI of the female R. tawarensis was higher in March, September and December indicating the onset of reproductive seasons, the GSI and oocyte size being directly correlated with gonadal development stages. Although, a greater proportion of mature male than female was detected during the study, the sex ratio showed that the overall number of female was higher than male. The ovaries had multiple oocyte size classes at every stage of gonadal development, thus R. tawarensis can be classified as a group synchronous spawner or a fractional multiple spawner. The spawning seasons of R. tawarensis were three times a year and September being the peak of the reproductive season and the female was the predominant sex. This species is classified as a group synchronous spawner. (PDF contains 8 pages)

The role of women in marketing of frozen fish in Lagos State of Nigeria

The involvement of women in the marketing of frozen fish in Lagos State (Nigeria) was examined in this study. Two hundred questionnaires were administered to fish marketers in five markets randomly selected within the Lagos metropolis based on their storage capacities. These markets were Balogun (500 tones), Idumagbo and Idumota (250 tonnes each) Obalende and Epetedo (37.5 tonnes each). From the study results, a greater percentage of women (64.2%) are actively involved in marketing of frozen fish in the study areas. Over 56% of these traders are retailers while about 33% are wholesalers. More than 91% of the marketers were found to be literate. A high percentage of the frozen fish are imported (68%), 27% from coastal fishing and 5% from riverine fishing. The commonest fish in the markets were titus (34%), sardine (32%), hake 19%, catfish 10% and argentine 5%. Catfish has the highest profit margin. The greatest problem of these traders is the lack of modern storage facilities and where available, the erratic power supply constitutes a problem

Preliminary study of the aquatic macrophytes of selected fish ponds and reservoirs in Makurdi, Benue State, Nigeria

A five months survey was conducted to identify the aquatic macrophytes in fishponds and reservoirs in Makurdi (Benue State, Nigeria) between August and December 1999. A total of 3-prominent aquatic macrophytes were identified: Ipomoea aquatica, Nymphae lotus and Echinochloa pyramidalis at two-study sites (site 1, receives organic manure effluent from a cattle ranch, site 2, receives inorganic fertilizer through application). Ipomoea aquatica were found restricted to site l, while Nymphae lotus and Echinochloa pyramidalis were found associated with site 2. Analysis of the results indicates high level of ammonia-nitrogen at site 1 compared to site 2. Mineral analysis of the plant tissues indicate high level of iron in Ipomoea aquatica and Nymphae lotus. Mineral concentration were found to be significantly higher (P,L, 0.05) in Ipomoea aquatica and Nymphae lotus when compared with concentration in Echinochloa pyramidalis

Food and feeding habits of Tilapia zilli (Pisces: Cichlidae) in Ondo State University fish farm

The food and feeding habits of Tilapia zillii in the fish farm of Ondo State University, Akungba - Akoko, Nigeria, were studied by gut analysis. Examinations of 150 specimens showed that Nymphea formed the main bulk of food consumed. Spirogyra, Pithophora and Compsopogon occurred frequently while Pistia detritus and plant remains featured less frequently. Variation in the frequency of occurrence of the various food items was observed among the various sizes of samples. The samples within the middle - size group fed on both higher plant and filamentous algae while the young and higher fish consumed exclusively filamentous algae. On the basis of food items found in the gut, Tilapia zillii was classified as primary consumers

Distribution and occurrence of bacterial fish diseases in the different cultural facilities of Lake Kainji area

Fish farming practices in the Lake Kainji Area of Nigeria are categorized under seven main cultural facilities, namely, earthen ponds/reservoirs, indoor/outdoor concrete tanks, plastic tanks, floating cages/hapas, aquaria, sewage and feral conditions. The presence of Bacteria isolates associated with diseased fish conditions varied significantly (P<0.05) with different cultural facilities. The highest bacteria isolates and bacterial disease incidence, 33% and 46% respectively, was associated with diseased fish in the indoor/outdoor concrete tanks. The least incidence of bacteria isolates (3.5%) and blue bacterial disease (3%) was associated with diseased fish in the aquaria and feral conditions. Nine Gram-negative and two Gram-positive bacteria genera were isolated during this investigation. Pseudomonas spp. (23.6%) and Staphylococcus spp. (14.3%), were the predominant Gram-negative and Gram-positive bacteria genera in the different cultural facilities, respectively. This paper highlights the relevance of occurrence and distribution of bacteria isolates associated with diseased fish to bacterial fish diseases under different cultural facilities

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 aquaculture

Preliminary study of the aquatic macrophytes of selected fish ponds and reservoirs in Makurdi, Benue State, Nigeria

A five months survey was conducted to identify the aquatic macrophytes in fishponds and reservoirs in Makurdi (Benue State, Nigeria) between August and December 1999. A total of 3-prominent aquatic macrophytes were identified: Ipomoea aquatica, Nymphae lotus and Echinochloa pyramidalis at two-study sites (site 1, receives organic manure effluent from a cattle ranch, site 2, receives inorganic fertilizer through application). Ipomoea aquatica were found restricted to site l, while Nymphae lotus and Echinochloa pyramidalis were found associated with site 2. Analysis of the results indicates high level of ammonia-nitrogen at site 1 compared to site 2. Mineral analysis of the plant tissues indicate high level of iron in Ipomoea aquatica and Nymphae lotus. Mineral concentration were found to be significantly higher (P,L, 0.05) in Ipomoea aquatica and Nymphae lotus when compared with concentration in Echinochloa pyramidalis

Nutritional and anti-nutritional analyses of Azolla africana Desv. and Spirodela polyrrhiza L. Schleiden as feedstuffs for fish production

The chemical composition of Azolla africana and Spirodela polyrrhiza cultivated in earthen ponds were determined. Crude protein contents of the samples were 28.9~c0.6 and 25.6~c0.2% dry matter for A. africana and S. polyrrhiza respectively. Dry matter, crude fibre and lipid contents of A. africana were higher (P<0.05) than values obtained for S. polyrrhiza. Mineral analyses showed that S. polyrrhiza contained higher levels of Na, S, Ca, Mg and Fe than A. africana. Except for Ca content in S. polyrrhiza, heavy metals (Ni and Zn) accumulation in Azolla were very high. There were no wide differences in the individual amino acid indexes except for methionine. Some anti-nutritional factors were determined. Cyanide, tannin and phytin contents of fresh weed samples were higher than sun-dried samples. A. africana contained more cyanide and tannin than S. polyrrhiza both in fresh and sun-dried forms

The distribution and feeding habits of a cichlid fish Oreochromis niloticus (Linnaeus) in Opa Reservoir, Ile-Ife

The distribution of Oreochromis niloticus was studied in Opa reservoir (Nigeria) using a graded set of gillnets while the food and feeding habits were studied using a castnet to collect the fish samples. About 90% of the fish specimens were caught near the reservoir bottom while about 69% of the specimens were caught within the inshore area of the reservoir. The species fed mainly on detritus, algae and higher plants. Feeding rhythm in O. niloticus started around 6.00 a.m. and reached a peak by 3.00 p.m. but then declined gradually until 6.00 p.m. These results can be utilized for the proper management of the fish species in the reservoir

The hydrology of a small fish pond at the University of Agriculture, Makurdi Experimental Fish Farm

The monthly and seasonal water requirements of a small fish pond (0.068ha; maximum capacity of 613.83m super(3)) at the University of Agriculture, Makurdi Fish Farm (Benue, Nigeria) were determined during the period of February to August 1996. The sources of water for the pond were rainfall, (103.4cm), run-off (6.3cm) and regulated inflow (95.0cm). The water loss for the period were Evapotranspiration, (106.74cm), Seepage (71.64cm) and regulated discharge (25.00cm). Evapotranspiration was identified as the main source of water loss while rainfall was the major source of water gain. The mean monthly water deficit was 24.56~c11.43cm while the mean monthly surplus was 9.84~c8.05cm. The quantity of water required to maintain the optimal water level in the pond was 474.00m super(3). Preliminary water budget of the study area showed that rainfed aquaculture can be effectively carried out at Makurdi during the months of June to October with supplementary inflows during the dry season months

Parasites and non-fish predators of tilapia with particular reference to the sustainable management of fisheries of Lake Kainji Nigeria

The fisheries of Lake Kainji, Nigeria, experienced a boom year following impoundment, then decline post impoundment and now is in a period of stabilisation of the fish resources. Several reasons have been advanced on factors responsible for these changes, but two outstanding factors are those of nutritional status and fishing methods of the lake. Two important fish families however continue to dominate the lake fisheries in daily fisherman catches: Clupeidae and Cichlidae (tilapias). Recent studies have also shown that the dominance of the tilapias and clupeids is an important factor in the understanding of the stability of fisheries of Lake Kainji. One area which has remained undiscussed concerns the parasites and non-fish predators of tilapias which can affect the population dynamics of tilapias. This paper examines therefore some aspects of the fisheries of Lake Kainji and the potential roles that parasites and non-fish predators of tilapias can contribute in developing strategies for consideration in the sustainable management of the fisheries