亜種

1. Origins, structure, and basic meaning

• Structure: 亜種, read あしゅ, is the biological noun subspecies.
• Basic usage: 同じ鳥の亜種を見比べる compares subdivisions of one species; 青い羽を持つ亜種 describes one by a feature.

2. Common pitfalls and similar expressions

• Subdivision within a species
  • 同じ鳥の shows that the forms belong within one species rather than representing unrelated species.