Evaluation of duckweed (Lemna minor) meal as partial replacement for fish meal on the growth performance of Indian major carp, Cirrhinus mrigala fry

An experiment was conducted under Laboratory culture conditions for 120days to evaluate the nutritional values and acceptability of Lemna minor as component in the diets of Cirrhinus mrigala fry. By replacing fish meal with Lemna minor at 0%, 15%, 30% and 45% inclusion levels, four different fish feeds comprising of Lemna, fish meal, GNOC(Groundnut Oil Cake), rice bran, soybean, salt and vitamin were used to formulate compound diets. The fries were fed twice daily, morning and evening at 5% body weight. The three inclusion levels of duckweed supported the growth of Cirrhinus mrigala fry but growth performances weight gain and growth rate was favoured by low inclusion of duckweed meal. However, highest body weight gain (%) was recorded in the group of fish fed diet (0% inclusion of duckweed) which was not significantly different (P<0.05) from 15% level inclusion of duckweed. On the basis of the findings, the study revealed that although fish fry fed diet of 15% duckweed dietary inclusion performs best result but fish meal was completely non-replaceable however, can be supplemented with duckweed up to an optimum level to produce cost effective feed.