对三角帆蚌内脏团、外套膜的组织化学研究表明：珍珠囊的存在刺激组织输送钙盐。钙盐的聚集经内脏团在营养吸收和循环系统运输路径；经外套膜存在内侧上皮细胞主动运输和循环系统运输路径。这两种路径的输送均由疏松结缔组织参与完成，并使钙盐在分布上存在一定的差异，这些差异对珍珠的质量有较大的影响。

Histochemistry and microphotograph were applied to studing the calcium distribution of the mantles and the visceral masses in Hyriopsis cumingii (Lea). The results show that the existence of the pearl sac will stimulate the tissue to transport calcium. The calcium may be transported both by the assimilation of nutriment or the circulatory system in the visceral mass and by the active transportation of the inner epithelium or the circulatory system in the mantles. The loose connective tissues participate in transporting calcium in the mantles and the visceral mass. There is a difference in the distribution of calcium between the mantles and the visceral mass. The quality of the pearl will be affected due to the difference.