noun
sea turtle
Refers to any marine turtle. In everyday Japanese, ウミガメ is the most common form.
ウミガメが砂浜に卵を産みに来た。
A sea turtle came to the sandy beach to lay eggs.
この水族館ではウミガメを見ることができる。
You can see sea turtles at this aquarium.
Mixed kanji-kana spelling, less common than ウミガメ or 海亀.
亀 is the general word for turtle or tortoise, while ウミガメ specifically means sea turtle.
Compound of 海 (umi, 'sea') and 亀 (kame, 'turtle'). The kana spelling ウミガメ is standard in modern usage.