Features of shape and size variability of blood ark (Anadara kagoshimensis) inhabiting biotopes in the northern part of the Black and Azov Seas were studied. Fourteen morphometric traits were measured for each blood ark shell. The principal component analysis extracted only one principal component (PC) whose eigenvalue is greater than 1.0. The PC 1 explained 84.5 % of the variation in morphometric traits and was interpreted to be an integral indicator of mollusk shell size. The variation of morphometric traits due to the size and asymmetry of the valves was subjected to correction using a Multiple General Linear Model with PC 1 as a continuous predictor and right or left valve as a discrete predictor. A cluster analysis was performed based on the residuals after size correction, as a result of which mollusk individuals were divided into four clusters. For mollusks from the Sea of Azov, a characteristic feature was an increased distance between pallial line and ventral shell margin. In turn, mollusks from the Black Sea exhibited an increase in the width of the posterior adductor scar. The observed morphological differences can be explained by different quantity and quality of food, since the soil composition in the biotopes studied is almost identical.

血舟（Anadara kagoshimensis）的形状和大小变异特征）研究了黑海和亚速海北部的栖息地。对每个血方舟壳测量了 14 个形态特征。主成分分析只提取了一个特征值大于1.0的主成分（PC）。PC 1 解释了 84.5% 的形态特征变异，并被解释为软体动物壳大小的综合指标。由于瓣膜的大小和不对称性而导致的形态特征变化使用多重一般线性模型进行校正，PC 1 作为连续预测器，右或左瓣膜作为离散预测器。基于尺寸校正后的残差进行聚类分析，将软体动物个体分为四个聚类。对于来自亚速海的软体动物，一个特征是上皮线和腹侧壳缘之间的距离增加。反过来，来自黑海的软体动物表现出后内收肌疤痕的宽度增加。观察到的形态差异可以用食物的数量和质量不同来解释，因为所研究的生物群落中的土壤成分几乎相同。