| Open water |
大水面 |
| open-type dam |
開口式壩 |
| Operating rule |
操作規程 |
| Operating status |
工況 |
| Operation |
作業 |
| Operation Plan of Disaster Prevention and Response |
災害防救業務計畫 |
| Operation Section |
作業課 |
| Operational research |
作業研究，運籌學 |
| Ophichthyidae |
蛇鰻科 |
| Ophichthys apicalis (Bennett) |
頂蛇鰻 |
| Ophichthys cephalozona Bleeker |
頸帶蛇鰻 |
| Ophichthys evermanni Jordan & Richardson |
愛氏蛇鰻 |
| Ophichthys macrochir (Bleeker) |
長身蛇鰻 |
| Ophichthys tuschidai Jordan & Snyder |
錦蛇鰻 |
| Ophichthys urolophus (Temminck & Schlegel) |
裾蛇鰻 |
| Ophidiidae |
鼬魚科 |
| Ophidion asiro Jordan & Fowler |
蓆鱗鼬魚 |
| Ophiocara aporos (Bleeker) |
無孔塘鱧 |
| Opisthognathus fasciatus Chan |
橫帶後頜 |
| Opisthognathus sp. |
一色後頜 |
