三种壳色硬壳蛤(Mercenaria mercenaria)的生长性状差异及通径分析

壳色是影响商品贝类经济价值的重要性状。本研究以不同壳色的硬壳蛤（Mercenaria mercenaria）群体为繁殖亲贝，采用个体间随机交配的方法，成功选育了白、红和杂3种壳色的子代群体，并在池塘培育至360日时测量了其壳长（X₁）、壳高（X₂）、壳宽（X₃）及活体质量（Y），并使用相关性分析、主成分分析和通径分析等方法，探究了不同壳色硬壳蛤在幼虫期和稚贝期的生长性状差异及壳形态性状（壳长、壳高、壳宽）对活体质量的影响。研究结果表明：在幼虫期，与白色和红色群体相比，杂色群体生长速度更快、变态率更高，但存活率低（P<0.05）；在稚贝期，白色群体表现出显著的生长优势（P<0.05）。相关性分析结果显示，3种壳色硬壳蛤的壳形态性状（X₁、X₂、X₃）与活体质量（Y）的相关系数均达极显著水平（P<0.01）。主成分分析和通径分析结果表明，硬壳蛤的壳长（X₁）是影响其活体质量（Y）的主要因素。本研究结果能够为不同壳色硬壳蛤良种选育提供重要理论依据和基础数据。

Differences in the growth traits and path analysis of the three shell colors of Mercenaria mercenaria

Shell color is an important characteristic affecting the commercial value of shellfish. In this study, populations of Mercenaria mercenaria with different shell colors were used as breeding parent shellfish, and the progeny populations of white, red, and mottled shell colors were successfully bred by random mating between individuals and were cultivated in a pond for 360 days. The shell length (X₁), shell height (X₂), shell width (X₃), and body mass (Y) were measured, and correlation, principal component and path analyses were used to explore the different shell colors of M. mercenaria. Differences in the growth traits between larval and juvenile clams and the effects of shell morphological traits (X₁, X₂, and X₃) on body mass were assessed. The results showed that the mottled population grew faster and had a higher metamorphosis rate at the larval stage than the white and red populations but had a lower survival rate (P<0.05). The white group had a significant growth advantage at the juvenile stage (P<0.05). The correlation coefficients between the shell morphological traits (X₁, X₂, and X₃) and body mass (Y) of the three shell colors of M. mercenaria all reached a very significant level (P<0.01). The results of principal component and path analyses revealed that the shell length (X₁) of M. mercenaria was the main factor affecting its body mass (Y). The results of this study provide an important theoretical basis and basic data for the selection and breeding of different shell colors in M. mercenaria.