that can crush little red sea urchins. 能够咬碎小红海胆
sea urchins sifting the accumulating drifts. 海胆,收集并过滤漂流物
Sand dollars flat sea urchins cluster together as a defense 成群的饼海胆叠加起来组成防御阵线
Urchins fell vast areas of kelp forest creating clearings know as urchin barrens 海胆吃掉了大片的海藻森林 把它们变成了不毛之地.
An army of sea urchins is mounting an attack. 一大群紫海胆正在发动进攻