Abstract
There is paucity of information on the suitable floating catfish fingerling/nursery production system for juvenile catfish which are in very high demand. The effects of enclosure shape, stocking density, water quality on production of catfish fingerlings and juveniles were evaluated by carrying out two experiments. Experiments involved the use of two plastic enclosure shapes (circular and rectangular of 60litres each) and dosage of eggs (5g, 10g, and 15g of eggs). There were 3 replicates per treatment (enclosure shape and dosage). Eggs were incubated and hatched in the enclosures. Data collected were number of fingerlings, weight and length, pH and water temperature inside and outside the enclosures were also monitored. Parameters monitored included number of juveniles, percentage of shooters and suspected cannibalized fish. Data were subjected to ANOVA. Results showed that mean water pH inside the enclosures were not significantly different (p>0.05) with respect to enclosure shape. Weight and length of fish at fingerling stage were affected significantly (p<0.001) by dosage. 5g dosage recorded highest mean weight (3.6g) and the length (6.7cm) of fish at fingerling stage while the 15g dosage had the least mean weight (2.0g) and length (5.0cm). There were no significant differences (p>0.05) in water temperature and pH within and outside the enclosure under different egg dosages, percentage of shooters and suspected cannibalized fish were not significantly different (p> 0.05) between enclosure shapes. However, the mean weight of fish in circular enclosure was significantly higher (p<0.001) than in rectangular enclosure. Fish in circular enclosures weighed 7.7g each while those in rectangular enclosures weighed 7.0g. Percentage survival and number of shooters were not significantly different (p>0.05) among the three stocking densities. In contrast, number of fish harvested and suspected cannibalized fish were affected significantly (p<0.001) by stocking densities. Length of fish harvested was significantly different (p<0.001) among the stocking densities. The higher the stocking density the shorter the length of fish harvested. The same inverse trend was observed in weight of shooters, stocking density at 60 fish/enclosure yielded the lightest shooters (6.4g) compared with the highest (8.3g) in 15 fish/enclosure. There was no significant difference (p>0.05) in number of shooters under the different stocking densities, however it is concluded that lower stocking density is preferred to higher stocking density. It is therefore recommended that enclosure of either shape could be adopted. DOI: 10.7176/JBAH/11-14-04 Publication date: July 31 st 2021
Highlights
Aquaculture is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants in controlled conditions (Jhingran, 1987)
Dosage effect on fish production Mean dosage rate was higher for number, weight and length of fingerlings, in the circular enclosure than the rectangular enclosure
It was observed that the number of fingerlings was highest in 15g for both enclosures and the lowest was recorded in 5g dosage respectively
Summary
Aquaculture is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants in controlled conditions (Jhingran, 1987). From an activity that was focused on freshwater fish, the cyprinids, it encompasses all aquatic environments and many aquatic species. World aquaculture has grown tremendously during the last fifty years from a production of less than a million tonnes in the early 1950 to 59.4 million tonnes by 2004. This level of production had a value of $70.3 billion of which 41.3 million tonnes, or 69.6 percent, was produced in China and 21.9 percent from the rest of Asia and the Pacific region. The Western European region contributed 3.5 percent with 2.1 million tonnes (valued at $5.4 billion), while the central and Eastern Europe region contributed 250,000 tonnes, or 0.4 percent
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