Study On The Optimization Of Pond Ecological Culture Of Eriocheir Sinensis In Gaochun

Based on Gaochun’s experience and thinking in Eriocheir sinensis culture for20years, we developed the technology of Eriocheir sinensis pond ecological culture by use of the model of Eriocheir sinensis-aquatic weeds-snail-mandarin fish-black shrimp. There are mainly three contents in this thesis.1. Study on growth characteristics and feeding techniques of Eriocheir sinensis in ecological culture pondTwo ponds in Gaochun Tuanjiewei fish area were selected. The area of ponds is1.7hm2,2.9hm2respectively and the depth of ponds is1.3-1.5m. The same stocking model and raising method were adopted. The law of growth and molt, and the logistic curve of body weight were derived from results. Meanwhile, the standing stock, feeding rate and feed coefficient of Eriocheir sinensis were analysed in every month. The feeding of fresh trash fish, artificial diet and raw coarse cereals (wheat, Soybean, corn, etc) were popular in Gaochun areas. Feed coefficient was4.5kg trash fish+lkg artificial diet+0.6kg raw coarse cereals in this model. Feeding plan was made according to weight gain and feed coefficient. Thereby the best feeding method, the better water environment and the greater grow speed were achieved based on the researches on standing stock, feeding rate, and daily food consumption.2. Effects of stocking density on average size, yield and survival rate of Eriocheir sinensisCompletely Randomized Design was adopted in this paper. Eight ponds in Gaochun Cangxi2814fish area were selected; and the area of ponds is0.67-0.80hm2and the depth of pond is1.3-1.5m. The stocking density of young Eriocheir sinensis is3750,5250,6000,6750,7500,10500,11250and12000individuals per hm2respectively. All ponds were under the same raising conditions. The results indicated that the relationship between size (Y) and stocking density (x) is Y=215.15-0.007x (R2=0.962)(P<0.05); the relationship between yield (Z) and stocking density (x) is Z=270.97+0.079x (R2=0.960)(P<0.05); whereas the relationship between survival rate and stocking density is not significant. Hence, the profit of Eriocheir sinensis culture will reach maximization if the size is suitable for market and the stocking density is improved. It recommended that the size of young Eriocheir sinensis with75%survival rate were120-140individuals per kg; the size of sale were170g per individual. The optimal density were less than6000individuals per hm2.3. Effects of snail requirement on average size, yield and survival rate of Eriocheir sinensisCompletely Randomized Design was adopted in this paper. Seven ponds in Gaochun Cangxi2814fish area were selected; and the area of ponds is0.67-0.80hm2and the depth of pond is1.3-1.5m. The stocking rate of snail is750,1070,2250,4500,5440,5630and6750kg·hm-2respectively. All ponds were under the same raising conditions. The results showed that the relationship between Eriocheir sinensis yield (Z) and snail stocking rate (x) is Z=528.138+0.228x-0.000029x2(R2=0.959)(P<0.05); the relationship between Eriocheir sinensis size (Y) and snail stocking rate (x) is Y=155.368+0.014x-0.0000017x2(R2=0.934)(P<0.05); the relationship between the Eriocheir sinensis survival rate (L) and snail stocking rate (x) is L=52.208+0.018x-0.0000023x2(R2=0.957)(P<0.05). The optimal snail stocking rate is4500kg·hm-2.