Cultivation of duckweeds lemna and spirodela as feed for nile tilapia | |
| Author | Hassan, Md. Shafiqul |
| Call Number | AIT Thesis no. AE-86-28 |
| Subject(s) | Tilapia Fish-culture |
| Note | A thesis submitted in partial fulfillment of the requirements for t he degree of Master of Science. School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Duckweeds Lemna Sp. and Spirodela Sp. were cultivated in septage fed earth ponds and their comparative nutritional values as feed for Nile tilapia ( Oreochromis niloticus ) were evaluated. The extrapolated mean dry yield of duckweed Spirodela grown in septage fed earth ponds for a period of 90 days was 20.31 tons/ha/yr which was almost double that of 10 . 90 tons/ha/yr for Lemna. The extrapolated long term dry yield of Lemna , and Lemna contaminated with Wolffia for a period of 160 days grown in septage fed earth ponds was 10.15 tons/ha/yr, and the productivity of Lemna decreased with an increase in Wolffia contamination. On the basis of growth rate and feed utilization efficiencies, fresh duckweed Lemna was a more suitable feed for tilapia in comparison to Spirodela when grown in concrete tanks. The optimum feeding levels of fresh Lemna for tilapia in concrete tanks were 5%, 4% and 3% (on dry weight basis) of the total body weight of fish per tank per day when they were 25 to 45 g, 45 to 75 g and 75 to 105 g in weight, respectively. Algal blooms, insect infestations, wind and loss of pigments and decay of duckweeds had noticeable affects on the growth of duckweed. High fish mortality was observed at the higher levels of feeding due to deficiency of dissolved oxygen. |
| Year | 1986 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Edwards, Peter |
| Examination Committee(s) | Wee, Kok Leong ;Lin, Chang Kwei |
| Scholarship Donor(s) | Roya l Thai Government ( King's ) |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1986 |