hòu yú / shì / yī zhǒng / gǔ lǎo / de / hǎi yáng / shēng wù / bèi chēng wéi / huó huà shí鲎鱼是一种古老的海洋生物,被称为活化石。The horseshoe crab is an ancient marine creature known as a living fossil.