Effects of protein levels in artificial pellet feed on growth and survival rate of black apple snail (Pila polita)

Abstract

The present study was conducted to evaluate the effects of different protein levels in diet on the growth and survival rate of black apple snail (Pila polita) in grow-out period. There were 3 replicates in each treatment and snails were fed with protein levels at 15% (P15); 20 (P20); 25 (P25); 30 (P30); 35 (P35). Two month old juveniles with initial body weight, shell height and shell width of (2.52 g; 23.26 mm and 16.42 mm) were reared in the tarpaulin tanks (1 × 1 × 1 m; 40 cm water depth) at the density of 100 ind./tank. After 4 months of rearing period, the average body weight, shell height and shell width of the snail reached highest value in P20 (28.36 g; 54.59 mm; 39.74 mm, respectively) and that was significant difference (pcompared to the remaining protein contents (P15, P25, P30, P35). The survival rate of snails in P25 (75.3%) was higher than in P15 (74.7%), P20 (74.3%), P30 (73.3%) and P35 (71.7%). However, the survival rate was not significant difference among treatments (p>0.05). Snails in P20 obtained the highest productivity (2.79 kg/m²) and it was significant difference (pkg/m²) and P35 (2.31 kg/m²). The results of this study showed that the growth rate and productivity of black apple snail were highest when feeding diet contained 20% protein. The requirement of protein for the black apple snail in grow-out period was 22.12%.