|
Intends to different geographic populations of cave mud crab larvae, C1 and C5 Phase crab as the research object, more systematic study of morphological characteristics, breeding performance, aims for the proposed hole mud crab breeding necessary theoretical basis and technical support. The main results of this study are as follows: 13 geographic populations intends cave ecological adaptability of blue crab larvae on the low-salt and morphological differences preliminary study intends points to understand the different geographic populations of blue crab larvae ecological habits and morphological differences, this study collected from northern Vietnam, China Beihai, Guangxi and Hainan Wenchang three geographic populations intends hole Scylla the artificial breeding Z1 larvae granted under experimental conditions, the adaptability of different salinity incubation experiment. Different geographic Population of proposed hole mud crab larval survival under different salinity conditions, developmental duration and Megalopa morphological traits of difference. The results show that: (1) under the same salinity conditions, the three geographic populations intends hole mud crab megalopa survival rate of newly hatched larval development Tai was a significant difference (P lt; 0.05). Three geographic populations intends hole the mud crab megalopa survival rate of newly hatched larval development Tai salinity of 32 and 29 were higher (20.0% and 26.7%, 23.3% and 23.3%, 20.0% and 26.7%, respectively), salinity below 29, the three geographic populations greater difference, where salinity was 26 when Hainan population and development Tai megalopa survival rate (26.7%) was significantly higher than the same salinity nurture the North Sea and Vietnamese populations (P lt; 0.05). (2) at a salinity of 20 to 32 under the Vietnamese population of newly hatched larval development Tai megalopa duration significantly shorter than the same salinity Hainan and the North Sea populations (P lt; 0.05), Hainan and North Sea populations no significant difference (P> 0.05). Morphological traits of (3) three geographic populations intends hole mud crab megalopa (head carapace width, carapace length, the amount of margin width) exists significant difference (P lt; 0.05), Vietnam intends hole Scylla megalopa morphological traits index value performance, while the North Sea and Hainan proposed hole mud crab megalopa morphological index value is small. The 2 Chinese five geographic populations intends hole mud crab larval morphological differences analysis to select different geographic populations intends hole the Scylla C5 Phase crab as the object of study, application of measurable character data, multivariate statistical analysis of different geographic populations contemplated hole Scylla larval comprehensive analysis of morphological variation characteristics compare different populations. According to the results of cluster analysis, Xiamen population first and Sanmen were clustered together, followed by Raoping populations, Hainan populations gathered finally gathered and the North Sea populations. According to the results of discriminant analysis, three, Xiamen, Raoping, the North Sea and the Hainan population discriminant accuracy were 80.0%, 63.3%, 70.8%, 81.3% and 78.1%, the average fitting a probability of 75.0%, discriminant accuracy The lower the rate, the higher rate of miscarriage of justice between the various populations. This shows that the five geographic populations form of a certain degree of difference, but this difference to a lesser extent, the morphological differences may be due to different populations due to genetic differences. 35 geographic the population intends hole mud crab larval ecological adaptability of low-salt environment intended to compare different geographic populations of points of the growth characteristics of the blue crab and adaptability to environmental salinity, of the three, Xiamen, Raoping, North Sea and Hainan populations intends hole Scylla crab were cultured under different environmental salinity conditions, a comparison of the growth and development of the five populations. The results: the molting period, five geographic populations intends hole Scylla C2 and C3 Phase larval molting interval there was no significant difference (P> 0.05). Salinity only the C3 Phase crab slough shell interval have a significant effect (P lt; 0.05), where salinity 12:00 Hainan population the C3 period of larval molting between the shortest 3.6 d. Five geographic populations of specific growth rate, the proposed hole Scylla crab salinity 12:00 carapace width and weight specific growth rate is higher than other salinity. Salinity 12:00 the Hainan populations A wide and weight specific growth rate highest salinity for 6:00 of the North Sea populations width specific growth rate and specific growth rate, Xiamen population weight is the lowest. Hainan population carapace width and weight specific growth rate higher than the population of the North Sea under the same salinity in the salinity of 6, 12 and 32, 20%, 10%, 5% and 19%, 10%, 11%; respectively. higher than the the Raoping population under the same salinity of 13%, 27%, 5% and 10%, 19%, 8%; respectively than the same salinity Xiamen populations above 10%, 16%, 1% and 20 %, 16%, 13%;, respectively, higher than the three populations in the same salinity 5%, 8%, 5% and 8%, 5%, 15%. Five geographic populations intends hole the mud crab crab growth tends to decrease with increasing environmental salinity. Carapace width increments, five geographic populations three times molting A wide incremental there are significant differences (P lt; 0.05), salinity 18:00 Hainan populations C1 to C2 of crab carapace width increments salinity for a minimum of 6:00. Salinity of 6, 12, 24 and 32, the the Hainan populations C1 to C2 of crab carapace width incremental respectively, compared with the same salinity North Sea populations small 11%, 6%, 13% and 12%, respectively; respectively, compared with the same the Raoping populations salinity of 20%, 25%, 31% and 14%; respectively, compared with the same salinity of Xiamen's population is 27% smaller, 11%, 9% and 0%; respectively, compared with three of the same salinity doors populations of 4%, 6%, 13% and 4%. Minimum salinity of 12 the Hainan populations C2 to C3 Phase crab carapace width increments, salinity 6:00 Beihai populations. Salinity of 12, 18 and 32, the Hainan populations C2 to C3 of crab carapace width increments were larger than the population of the North Sea under the same salinity 66%, 16% and 7%; respectively, compared with the same salinity Raoping populations 28%, 22% and 4%; respectively than the same salinity Xiamen populations large 20%, 14% and 10%; larger than the three populations in the same salinity 30%, 14% and 21%. Salinity 12:00 Hainan, the North Sea and three populations C3 to C4 period Tsai highest average increment of crab carapace width, respectively, 2.77,2.71 and 2.71 mm; the salinity 6:00 RAOPING population minimum. Salinity of 6 and 12, the Hainan population C3 to C4 of crab carapace width increments were larger than the population of the North Sea under the same salinity 27% and 2%; respectively, compared with the the Raoping populations under the same salinity 34% 31%; Xiamen populations under the same salinity 20% and 7%, respectively; respectively, than the same salinity three populations of 13% and 2%.
|