| The Chinese mitten crab, Eriocheir sinensis is one of the most important freshwater products in Chinese aquaculture. Crab efficient mode of production, growth characteristics, such as crab and survival has been the focus of attention of producers and researchers. They all hope E. sinensis to be able to develop a production of high quality and large, but the pond is too large to statistics. Therefore, cages are placed in the ecological pond to culture E. sinensis, through small-scale cage culture, to explore the growth characteristics and survival rate of E. sinensis, to assess the pros and cons of different specifications of maternal, Provide basic data for the growth of E. sinensis, provide materials and data for the breeding of E. sinensis. The concrete research content is as follows:1. The comparative study on growth characteristics of different specifications of female parent offspring of the Chinese mitten crab. E. sinensis was farming in crab cages placed in the ecological pond, four handlings were setting according to the different female crab specifications, A group: offspring which female weight is 175.7 ± 5.3 g; B group: offspring which female weight is 150.4 ± 5.8 g; C group: offspring which female weight is 125.6 ± 5.5 g; D group: offspring which female weight is weight 100.2 ± 5.9 g. Each group has four parallel tests, every parallel has 10 male crabs, 20 female crabs. Each cage stocking 500 E. sinensis, Altemanthena philoxeroides were hidden objects, breeding started from Megalopa time with same and suitable growth environment. Excel and SPSS 22.0 software are applied for statistical analysis of data. After 158 days of cultivation, the weight of A, B, C and D group increased from 6.0 ± 0.5 mg to 7 599.8 ± 954.78, 6 232.7 ± 638.68, 6 112.4 ± 854.63, 5 316.0 ± 745.25 mg; 1 266.6, 1 038.8, 1 018.7 and 8 86.0 times respectively, the specific growth rate of A group was significantly higher than D group(P < 0.05). The weight of A group was significantly higher than B, C, D group after 6-11 times molting(P < 0.05); The weight of D group was significantly lower than A, B, C group after 6, 7, 10, 11 times molting(P < 0.05). The shell length of A group was significantly longer than B, C, D group after 7, 8, 10, 11 times molting(P < 0.05); The shell length of D group was significantly less than A, B, C group after 11 times molting(P < 0.05). Except 3 times molting, the shell width of A group was significantly wider than B, C, D group(P < 0.05); The shell width of D group was significantly less than A, B, C group after 9, 11 times molting( P < 0.05). Except 3, 6 times molting, the body height of A group was significantly higher than B, C, D group(P < 0.05); The body height of D group was significantly lower than A, B, C group after 2, 8, 9, 10, 11 times molting(P < 0.05). The best composite indicator(weight, shell length, shell width, body height)of the juvenile crab was A group which was significantly better than B, C, D group(P < 0.05); followed were B, C group, further was D group, B and C group had no significant difference( P > 0.05), but were significantly better than the D group. B group had the highest survival rate 1.4%, 3.6%, 4.6% higher than A, D and C group respectively; followed was A group 2.2%, 3.2% higher than D and C group respectively; furthermore was D group, 1.4% higher than C group. Systematical study indicates that on the one year seed breed phase, the offspring of large size female parent had a superior growth traits trend to small size female parent.2. The comparative study on growth characteristics of complete breeding and wild populations of Chinese mitten crab. In order to compare the growth of the progenies of breeding population and wild population of Chinese mitten crab, cages were placed in ecological ponds to conduct Chinese mitten crab breeding experiment. Three treatments were designed based on different female parent sources and specifications. A treatment: the progenies of breeding population, female parent weight are(150.39±5.82)g, male parent weight are(300.23±9.61)g;B,C treatment: the progenies of wild population, female parent weight are(150.47±6.28) g and(250.33±8.68)g respectively, male parent weight are both(300.56±10.27)g. Each treatment had four replicates, each cage stocking 500 Chinese mitten crabs, camouflaged by aquatic weed and began to breed from the megalopa time, maintaining the same growth environment and appropriate growth. After 158 days of culture, A, B and C treatment weight increased by 1 273.00, 1 258.17 and 1 363.95 times respectively. C treatment index is the best treatment when grew into crab species, C treatment is significantly better than A and B treatment in weight, carapace length and carapace width(P <0.05). Treatment A survival rate is the highest, 1.40%, 3.00% higher than B and C treatment respectively. The comprehensive studies showed that the growth traits of wild large size female progenies were better than wild and breeding small size female progenies, maternal effect were existed. Breeding population can better adapt to the pond water culture environment than the wild populations.3. The study of relationships between growth, molt and accumulated temperature of the Chinese mitten crab. To study the relationship between growth, molt and effective accumulated temperature of the Eriocheir sinensis, The cages were placed in the middle of the ecology pond to culture E. sinensis. The temperature logger were underwater penetration of the probe is 20 cm, cleaning once a week, Record time interval for 20 minutes at a time, Check at least every morning and evening once a day. Each cage stocking 500 Megalopa, Altemanthena philoxeroides were hidden objects, breeding with same and suitable growth environment, Excel and SPSS 22.0 software are applied for statistics analyse of data. After 158 days of cultivation, juvenile crab molted 11 times and developed into the crab grows,the average survival rate was(28.43 ± 4.61)%, the average temperature was(24.4 ± 0.05)℃, the total effective accumulated temperature was(3040.4 ± 244.16)℃·d, and with the E. sinensis molt, the growth trend of effective accumulated temperature is mostly close to exponential function(y = 40.056e0.2683 x, R2= 0.9901), the growth trend of cumulative effective accumulated temperature was mostly close to the polynomial( y = 33.336x2-115.05x+196.14, R2 = 0.9978). With the growth of the effective accumulated temperature, the specific growth rate showed exponential growth of relations(y = 20.926e-0.005 x, R2 = 0.933 3). The correlation between cumulative effective accumulated temperature and shell length, shell width, body height is very significant, with the growth of the cumulative effective accumulated temperature, shell length, shell width, body height showed exponential growth of relations. |
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