Table 2: Mean essential amino acid
values (g/100 g protein) of four species of
duckweed 1 compared to FAO reference EAA
pattern.
Amino acids
Mean ± SD FAO reference protein
Arginine
4.54 ± 0.64
-
Histidine
1.78 ± 0.42
-
Isoleucine
3.61 ± 0.37
4.2
Leucine
6.68 ± 0.58
4.8
Lysine
4.01 ± 0.43
4.2
Methionine
0.90 ± 0.15
2.2
Phenylalanine 4.16 ± 0.39
2.8
Threonine
3.12 ± 0.40
2.8
2
-
1.4
Tryptophan
Valine
4.39 ± 0.64
4.2
Tyrosine
2.82 ± 0.44
-
1
L.gibba, S. polyrrhiza, S. punctate and W.
Columbiana
Destroyed during analysis
2
Source: modified from Culley et al. (1981)
Conclusion:
Duckweeds have received much attention
because of their potential to remove mineral
AgriKultuur |AgriCulture
contaminants from wastewater. Definitive
information has been published on the
production and chemical composition of these
plants, and their environmental requirements
have been clearly determined. Information on
the cultivation techniques of many duckweed
species is also available. Due to their rapid
growth, attractive nutritional properties
and relative ease of production, duckweeds
have generated renewed interest among
fish nutritionists on their use as possible
alternative sources of fish feed.
References:
Caulton M.S. The Biology and Farming of
Tilapia in Southern Africa.
Chhorn Lim, Carl D. Webster – Editors. Tilapia:
Biology, Culture, and Nutrition.
FAO: Nutritional requirements of Nile Tilapia.
www.fao.org/fishery/affrisspecies-profiles/nile-
tilapia/nutritional-requirements/en/
FAO: Fisheries and Aquaculture Technical
Paper 531. Use of algae and aquatic
macrophytes as feed in small-scale
aquaculture.
E-mail: [email protected]
12