海亀

1. Origins, structure, and basic meaning

• Structure: 海亀(うみがめ) refers to a turtle that lives in the sea.
• Basic usage: It is used when discussing sea-turtle ecology or observation. Typical patterns are 海亀を観察する and 海亀の一生.

2. Common pitfalls and similar expressions

• Connect the spelling and reading
  • The word combines 海 and 亀 and is read うみがめ; the second element begins not with か but with が.
• Do not assume grammatical number
  • The Japanese noun itself does not mark singular or plural, so quantity must be inferred from a number expression or context.