2 sentences

1. 海马主要分布在热带和温带的温暖海域。

   hǎi​mǎ zhǔ​yào fēn​bù zài rè​dài hé wēn​dài de wēn​nuǎn hǎi​yù.

   Seahorses are mainly distributed in the warm waters of tropical and temperate zones.

   Source: Dong Chinese Dictionary

2. 海马在人类空间导航和记忆巩固中起着关键作用。

   hǎi​mǎ zài rén​lèi kōng​jiān dǎo​háng hé jì​yì gǒng​gù zhōng qǐ zhe guān​jiàn zuò​yòng.

   The hippocampus plays a key role in human spatial navigation and memory consolidation.

   Source: Dong Chinese Dictionary