Studies On Quantitative Characters,Nutrient Components And Larval Ecology Of Japanese Dosinia(Dosinorbis Japonica)

In this paper,the species was identified by classical analysis and molecular analysis,and the relationship between shell type and quantitative and qualitative characters of Korean population was studied by using multivariate analysis method.The nutrient components were analyzed by amino acid analyzer,and the effects of pH,temperature,salinity and culture density on the growth and development of planktonic larvae were studied by conventional ecological method.It provides a theoretical basis for improving the biological characteristics of the clam,revealing the nutritive value of the clam,and the rational regulation of the water quality during the cultivation of the Seedling species on a large scale.The results are as follows:1?Shell path Analysis of Korean population of Japanese Dosinia1)The volume index and convexity index were 0.4729 ±0.0203 ~ 0.5018±0.0197,respectively.The ratio of soft parts to the total volume was less and the meat yield was less.Both the lateral circular index and the lateral elliptic index are close to1,and the shell shape is close to circular.2)Principal component analysis showed that the volume index,extension index and convexity index were all greater than 1,and the contributions of these three groups accounted for 91.4% of the shell index.The characteristic root of capacity exponent is 2.451.The contribution value is 35.0.3)Correlation analysis,co-linear analysis,multivariate regression analysis and path analysis were used to study the relationship between quantitative characters of clam japonica.The results of correlation analysis showed that there was a significant phenotypic correlation(P < 0.01)among the characters of the tested clam,and the collinear analysis eliminated the shell length which had serious collinearity with each shell trait,and the path analysis showed that,Shell weight is the main character directly affecting total weight,shell cavity volume and shell width are the main characters directly affecting soft weight,shell width and total volume are main characters directly affecting shell weight,total weight is the main character directly affecting total volume and shell cavity volume.Shell weight is direct.By using stepwise regression method,the optimal regression equations of shell size on volume and weight were established,which could provide theoretical basis for breeding and breeding of clam japonica.2?Analysis of nutrient components in Korean population of Japanese Dosinia1)Protein,crude fat content is relatively low,about 0.512(wet weight)and 1.22 kum,glycogen content is relatively high,about 3.93%.2)The first limiting amino acids are methionine metamet and cystine.3)The content of unsaturated fatty acids in lipids was about 65%,and the total contents of EPA and DHA reached 21.46%,and the content ratio was about 1: 1.3,the influence of environmental stress on the development and growth of planktonic larvae of Japanese Dosinia.1)in the range of 6.8 ~ 8.4,the higher the survival rate is,the higher the growth rate of shell is,the higher the survival rate is.2)The survival rate of planktonic larvae at 25 ? and 33 ? was higher than that at 17 ?,and the growth rate of shell length increased with the increase of temperature in the range of 25 ?-33 ?.3)The survival rate of larvae in planktonic stage was higher in 20 and 30 gradient groups.When salinity was lower than 15 and above 35,all larvae died,and the growth rate of 30 shells was the fastest.4)in the range of 3-12 individual/ ml,with the increase of density,the survival rate of larvae decreased gradually,and the growth rate of shell length decreased.