长江下游日本沼虾形态特征及主要性状对体重的影响

Morphological Characteristic of Macrobrachium nipponensis in Lower Reaches of the Yangtze River and Effects of Main Morphological Factors on Body Weight

在长江下游安庆和常熟江段随机采集2 234尾日本沼虾(Macrobrachium nipponensis)样本,测量了全长、体长、额剑长、头胸甲长、头胸甲宽、腹部长、腹部宽、尾扇长、第二步足长、额剑上刺数及额剑下刺数等22项形态性状。采用通径分析方法计算了雌雄群体主要形态性状对体重的通径系数和决定系数,并对各性状影响体重的效应进行了分析。结果显示:额剑上刺数和额剑下刺数与体重的相关性不显著(P>0.05),而其余性状与体重相关性极显著(P<0.01),雌雄群体对体重影响最大的3个性状均为全长、体长和第二步足长。经通径分析及回归显著性检验,建立雌雄群体多元回归方程分别为W♀=-2.383+0.021X1+0.027X2+0.029X3+0.032X4+0.027X5和W♂=-3.321+0.011X1+0.053X2+0.024X3+0.051X4+0.021X5+0.032X6,两方程的多元回归系数(r2)分别为0.910 2和0.892 0,回归关系均达到极显著水平(P<0.01)。

In order to study the effects of morphological characters on body weight of Macrobrachium nipponensis in lower reaches of the Yangtze River,2234 individuals were randomly collected from two sections of Anqing and Changshu.22 morphological characters of these samples were measured,including total length,body length,rostrum length,carapace length,carapace width,abdomen length,abdomen width,tail fan length,second pereiopod length,number of upper frontal eminence spin,number of lower frontal eminence spin and so on.Method of path analysis was used to calculate path coefficients and determination coefficients of male and female colony,by taking body weight as dependent variable and nine morphological attributes as independent variables.The results showed that correlation coefficient between each character and body weight achieved significant difference(P<0.01)except number of upper frontal eminence spin(P>0.05)and number lower frontal eminence spine(P>0.05),and three top effective factors were total length,body length and second pereiopod length.After excluding insignificant factors,the multiple regression equations were established as W♀=-2.383+0.021X1+0.027X2+0.029X3+0.032X4+0.027X5(r2=0.910 2)and W♂=-3.321+0.011X1 +0.053X2+0.024X3+0.051X4+0.021X5+0.032 X6(r2=0.892 0),and the regression relation of above two equations both reached significant level(P<0.01).