单语范例（未经PONS编辑处理）
英语
- In non-mammalian animals, the zona pellucida (called vitelline layer) plays an important role in preventing cross-breeding of different species, especially in species that fertilize outside of the body (e.g. fish).en.wikipedia.org
是否要添加一些单词、短语或翻译？
请发送新条目。