不同规格中华绒螯蟹成蟹的形态特征和组织系数比较

Morphological characters and tissue indices of adult Chinese mitten crabs(Eriocheir sinensis)with different body mass

为探究中华绒螯蟹(Eriocheir sinensis)成蟹规格与其形态特征及组织系数的关系,本研究综合运用形态特征量化分析及多元统计分析比较了不同规格中华绒螯蟹(雄体:100~400 g;雌体:50~300 g)的形态特征差异。同时比较了不同规格中华绒螯蟹的性腺指数(Gonadosomatic index,GSI)、肝胰腺指数(Hepatosomatic index,HSI)、出肉率(Meat yield,MY)及总可食率(Total edible yield,TEY)等组织系数差异,并在此基础上建立中华绒螯蟹体质量、壳长及壳宽等形态参数与其性腺发育状态之间的回归关系。结果表明:(1)不同规格雄蟹有13个形态特征差异显著,而雌蟹仅有11个形态特征差异显著,主要表现为大规格中华绒螯蟹与头胸甲侧面相关形态特征的数值显著较高,而与头胸甲宽度和步足长度相关形态特征的数值显著较低;(2)形态特征主成分散点图显示,不同规格中华绒螯蟹虽有部分个体相互重叠,但大体可以形成较为集中的区域;(3)就组织系数而言,大规格中华绒螯蟹(雄体≥300 g、雌体≥150 g)GSI显著较低,但HSI、MY及TEY等指标显著较高。综合分析表明,不同规格中华绒螯蟹的形态特征及组织系数均存在明显差异,并且中华绒螯蟹规格及头胸甲尺寸与GSI呈显著负相关关系,研究结果为商品蟹的选购及亲本蟹的挑选提供了理论依据。

To investigate the relationship between morphological characters and body mass of adult Chinese mitten crabs Eriocheir sinensis,19 morphological characters were measured and compared among E.sinensis with different body weights by quantitative and multivariate analysis,and the hepatopancreas index(HSI),gonadosomatic index(GSI),meat yield(MY)and total edible yield(TEY)of these crabs were compared either.The results showed that:(1)There were 13 and 11 significantly different characteristics detected in male and female E.sinensis respectively,and the values of morphological characteristics related to the length of carapace significantly increased with E.sinensis body weights increasing,but the values related to carapace width and feet length significantly decreased with E.sinensis size body weights increasing.(2)The results of principal component analysis(PCA)revealed that the polts represents different-sized individuals were relatively separated with only a slight overlap between group,indicating a quite different morphology of the individuals with different sizes.(3)Significant difference were detecte in tissue indices among differentsized crabs,and the larger crabs(Male≥300 g;Female≥150 g)had significantly lower values of GSI but significantly higher values of HSI,MY and TEY than the smaller ones.All in all,different-sized E.sinensis had significant differences in morphological characteristics and tissue indices,and they showed a significant negative correlation with GSI,which would provide a valuable reference for commercial and broodstock crabs selection.