Effect of L. minor at Fluctuating Concentrations Used a Considerable Impact on the Growth Dynamics of Grass Carp Fingerlings
Amrita Giri Das *
Department of Aquaculture, School of Agriculture, Sanjeev Agrawal Global Educational (SAGE) University Bhopal, M.P, India.
Shriparna Saxena
Department of Aquaculture, School of Agriculture, Sanjeev Agrawal Global Educational (SAGE) University Bhopal, M.P, India.
Pijush Payra
Department of Fisheries Science, Ramnagar College, Purba Medinipur, W. B., India.
*Author to whom correspondence should be addressed.
Abstract
Background: Duckweed is a locally available aquatic plant with potential as a sustainable feed ingredient in aquaculture.
Aims: This study evaluated the effect of graded dietary inclusion of Lemna minor on the growth performance, feed utilisation, and survival of grass carp (Ctenopharyngodon idella) fingerlings reared in earthen ponds.
Methods: A total of 180 fingerlings were distributed among 12 earthen ponds at 15 fish per pond. Four dietary treatments were assessed: an unsupplemented control and basal diets containing 5%, 10%, and 20% L. minor, designated T1, T2, and T3, respectively. Fish with an initial mean weight of 66.55 g and mean length of 13.45 cm were fed at 5% of body weight twice daily for six months. Growth performance was assessed using net weight gain, percentage weight gain, specific growth rate, feed conversion ratio, and survival.
Results: Dietary supplementation with L. minor improved growth performance and feed utilisation compared with the control. Treatment T2 recorded the highest net weight gain of 574.20 ± 1.03 g, percentage weight gain of 45.31 ± 0.36%, and specific growth rate of 1.41 ± 0.003. It also showed the lowest final feed conversion ratio of 1.76 ± 0.006. Survival was 100% in all supplemented groups, compared with 80.71% in the control. Statistical analysis indicated significant differences among treatments at p < 0.05. These findings support its potential use in practical aquaculture feeding.
Conclusion: Moderate dietary inclusion of L. minor, particularly the T2 treatment, enhanced growth, feed utilisation, and survival of grass carp fingerlings under earthen-pond culture conditions.
Keywords: Duckweed, Lemna minor, grass carp, Ctenopharyngodon idella, aquafeed, dietary supplementation, growth performance, feed conversion ratio, survival, earthen ponds