What does anadromous mean?

What does anadromous mean?

• A. Fish that migrate from saltwater to freshwater to spawn.
• B. Fish that stay in freshwater their entire lives.
• C. Fish that migrate from freshwater to saltwater to spawn.
• D. Fish that reproduce on land.

Answer: (A)

Anadromous describes fish that live in saltwater for most of their lives but migrate back to freshwater to reproduce. This pattern is seen in species like salmon, which mature in the ocean and then return to rivers to spawn.

So, the best choice states migrating from saltwater to freshwater to spawn, which fits the classic anadromous life cycle. The other patterns don’t match: staying in freshwater their whole lives describes non-migratory freshwater residents; migrating from freshwater to saltwater to spawn describes catadromous species (like some eels); reproducing on land isn’t applicable to true fish.