A protein substance that is the organic basis of mollusk shells.
贝壳硬蛋白作为软体动物贝壳有机基质的蛋白质
The pearly internal layer of certain mollusk shells, used to make decorative objects.
珠母层某些软体动物壳内似珍珠的层，用来做装饰物
An animal, such as an insect or a mollusk, that lacks a backbone or spinal column.
无脊椎动物缺少脊骨或脊柱的动物，例如昆虫或软体动物
