淀山湖秀丽白虾形态特征对体质量的影响效果

Effects of morphometric traits on body weight for Exopalaemon modestus in Dianshan Lake

秀丽白虾是淡水湖泊中的重要经济种类。作为渔民的主要经济来源之一,研究其表型性状有助于提高人工养殖的存活率,利于野生资源的可持续发展。随机均匀选取淀山湖秀丽白虾140尾,体质量为0.6~3.1 g。利用电子游标卡尺测定体长（X1）、额剑长（X2）、头胸甲长（X3）、头胸甲宽（X4）、腹部长（X5）、腹部宽（X6）、尾扇长（X7）及体质量（Y）8个形态性状。以个体形态性状为自变量,体质量为因变量,采用相关分析、通径分析和多元回归分析等研究方法分析形态性状对体质量的影响效应。结果显示,秀丽白虾的7个形态性状与体质量间的相关系数均达到极显著水平（P〈0.01）;经通径分析显示,体长、额剑长和腹部长对体质量的通径系数达到显著水平（P〈0.05）,其中体长对体质量的直接影响最大,是影响体质量的最主要性状;所选形态性状与体质量的复相关指数为0.855,表明所选形态性状的确是影响体质量的关键形态性状;逐步回归分析建立以体质量（Y,g）为因变量,体长（X1）、额剑长（X2）和腹部长（X5,mm）为自变量的多元回归方程：Y=-3.195＋0.060X1＋0.038X2＋0.041X5。因此,以上形态性状为秀丽白虾选育提供了测度指标。

White shrimp, Exopalaemon modestus, is the important economic species in freshwater lakes. As one of the economic sources for fishermen, studying morphometrie traits will help to improve the smrvival rate of artificial breeding, and benefit the sustainable development of wild white shrimp in Dianshan Lake. 140 individuals were randomly sampled in Dianshan Lake. The body weight was 0.6 - 3.1 g. Seven morphometric traits including the body length （X1） , length of upper frontal eminence （ X2 ） , carapace length （ X3 ） , carapace width（X a）, abdominal length（X5）, abdominal width（X6）, tail length（X7） and body weight （Y） were measured. The effects of morphometric traits on body weight were analyzed by using multivariate analysis methods including correlation analysis, path analysis and multiple regression analysis based on taking morphometrie traits as independent variables, and the body weight as dependent variable. The results showed that all seven con＇elation coefficients were at very significant levels （ P 〈 0.01 ） between each morphometric trait and the body weight. The path analysis revealed that the path coefficients of the body length, length of upper frontal eminence, and abdominal length to the body weight reached a significant level （P 〈 0.05 ）. Among three attributes above, direct effects of body length on body weight were greater than that of indirect effect. Body length was the key factor to the body weight （Y）. High multiple correlation index （0. 855） indicated that the main variables have been selected. Body length （X1 ）, carapace length （X2 ）, and abdominal （Xs） length were used to establish the multiple regression equation, which was Y = -3. 195 ＋ 0. 060X1 ＋ 0. 038X2 ＋ 0. 041 X5. The selected morphometric traits can provide theoretical measure target for selective breeding of white shrimps.