the flat ciliated free-swimming larva of hydrozoan coelenterates
例句
用作名词 (n.)
In the adult, or medusa stage of a jellyfish, they can reproduce sexually by releasing sperm and eggs into the water, forming a planula. 在海蜇成体或水母体阶段,它们通过将精子和卵于释放到水中形成浮浪幼体而进行有性繁殖。