Studies On Cage Culture Of Bighead Carp (Aristichthys Nobilis) By Hanging Feed Bag In Reservoir

Bighead carp(Aristichthys nobilis) is one of major cultured carps in China. The cage culture of bighead carp in reservoir by feed bag hanging (FBH) method is one of the new culture techniques in aquaculture. In this study, two experiments were conducted to investigate the growth performance of bighead carp using this new technique. In Experiment 1, fingerlings of bighead carp with the same size (0.45-0.46 kg/fish) were reared in different stocking densities (10, 20, 30, 40 and 50 fish/m~2). In Experiment 2. fingerlings with different sizes (0.09-0.10, 0.19-0.20, 0.45-0.46, 0.78-0.80, 1.00-1.03 kg/fish) were reared in the same stocking density (30 fish/m ). These two experiments included ten groups in total, with three replicates in each group. The feeding rate for each group was almost same, and the feeding rate and feed amount for every replicate in each group were equal. The main findings are as follows:1. In Experiment 1. growth equation of bighead carp was y = 0.2747x - 0.7318. in Experiment 2, growth equation was y = 0.2732x - 0.6565.2. In Experiment 1, the growth rate, feed coefficient and input-to-output ratio were significantly affected by stocking density through variance analysis (P < 0.01) .As the stocking density increased, the growth rate decreased; however, the feed coefficient and input-to-output ratio increased.3. In Experiment 2, the growth rate and feed coefficient were significantly affected by fingerling size (P < 0.01). As the fingerling size increased, the growth rate decreased and the feed coefficient increased; but the fingerling size did not significantly influence the input-to-output ratio, when the density increased, the input-to-output ratio did not van-obviously (P >0.05).4. In general, the experiments data indicate that for FBH method in the cage cultureof bighead carp, the best stocking density is 20-30 fish/m~2 and the standard size is between 0.45-0.80 kg/fish.5. The results from these two experiments about the FBH method for the culture of the bighead carp showed that this technique fits the carp’s feeding habit and can effectively boost its growth rate. This method can also minimize feed loss, increase the feed efficiency, decrease the feed cost and save the feeding time, so it is applicable for the intensive culture of bighead carp and can bring good economic benefits. Based on our results, we suggest that HFG method would improve the production of bighead carp aquaculture and have a broad application.