Food preference and growth of grass carp, Ctenopharyngodon idella (Cuvier and Valenciennes, 1844) fed some aquatic and terrestrial plants

The present study was carried out to examine 6 plants including aquatic and terrestrial plants on food preference and growth of grass carp. 7 experimental treatments with three replicates were considered. The experimental treatments were ponds containing T1: M. spicatum, T2: C. demersum, T3: A. filiculoides, T4: L. minor, T5: C. dactylon, T6: M. sativa and T7: M. Spicatum + C. demersum + A. filiculoides + L. minor + C. dactylon + M. sativa. 12 grass carps (20 g) were added to each experimental pond. After 5 months, the fish body composition was assessed. According to results, the higher values of fish weight gain rate were obtained in treatments T4 (3.13 g), T6 (2.93 g) and T1 (2.95 g) compared to other experimental groups (p<0.05). Also, the highest percentage of body protein and lipid content were observed in T4 and T1. In addition, the biomass and percentage of examined plants decreased after delivery of grass carps to each pond over the course of the experiment, but higher decreases were recorded for T4 and T1. The mean values of relative growth rate were higher in T4 and mixture of all plants (p<0.05). Also, the highest fish biomass was recorded in T1 and T4 (p<0.05). In conclusion, our results showed that T4 and T1 have higher adaptability compared to other examined plants in the present study and these two plants could be used for feeding grass carp in aquaculture.