亀の子

1. Origins, structure, and basic meaning

• Structure: 亀の子, read かめのこ, is a noun for a baby turtle or turtle hatchling.
• Basic usage: 水槽の亀の子が休む refers to one in a tank; 亀の子は水辺へ進む makes the hatchling moving toward water the topic.

2. Common pitfalls and similar expressions

• Internal の in 亀の子
  • The の is built into the expression meaning turtle's young; it is not an external possession marker added by the sentence.