Head to head
American Eel vs Coho Salmon
An American eel and a coho salmon both undertake dramatic migrations between fresh water and the ocean, yet their life cycles run in exactly opposite directions, making them a genuine mirror image of one another.
| American Eel | Coho Salmon | |
|---|---|---|
| Scientific name | Anguilla rostrata | Oncorhynchus kisutch |
| Migration type | Catadromous (fresh water to sea) | Anadromous (fresh water, sea, fresh water) |
| Birthplace | Sargasso Sea | Freshwater rivers and streams |
| Spawning location | Sargasso Sea | Freshwater rivers and streams |
| Time in fresh water before first ocean trip | Most of its life, often decades | About 18 months |
| Dies after spawning | Yes | Yes |
| Notable extra ability | Can cross land through wet grass | None comparable |
| Conservation status | Endangered | Near Threatened |
American Eel vs Coho Salmon: common questions
How are the life cycles of the American eel and coho salmon opposite?
The American eel is born in the Sargasso Sea and spends most of its life growing in fresh water before returning to the ocean to spawn, while the coho salmon is born in fresh water and spends most of its growth period in the ocean before returning to fresh water to spawn, making the two species mirror images of each other's migration pattern.
Do both the American eel and coho salmon die after spawning?
Yes, both species undertake a single, final reproductive migration and die shortly after spawning, a life history strategy called semelparity that neither fish deviates from, regardless of which direction their migration runs.
Can the American eel really travel over land like people say?
Yes, a young American eel can wriggle short distances across damp grass or mud, letting it reach isolated ponds and wetlands with no direct water connection to a river, an ability the coho salmon, which stays within connected river and ocean systems its whole life, does not share.