#anadromous

Distribution: Widely found in the northern Pacific Ocean, migrates to freshwater for spawning.

Did you know coho salmon are anadromous? That means they hatch in freshwater streams spending about a year there before migrating out to the ocean to feed and grow! They will return to the same stream areas to spawn later in life. (Photo: Adam Baus. Image description: A school of salmon swimming in a shallow stream.)

Pacific lamprey, Entosphenus tridentatus.  Watching lamprey move up a gradient or over a barrier is very cool: rather than swim, they use suction to grab the rocks with their mouths and inch upwards that way.  The Fish and Wildlife service has a great video showing lamprey climbing.

Distribution: Widely found in the northern Pacific Ocean, migrates to freshwater for spawning.

Pacific lamprey, Entosphenus tridentatus.

They're salmonids, so they develop kypes (Those, like, hooks on the snouts of salmon during breeding season that every1 knows about.) Like most salmon, not salmonid, just salmon, they're anadromous, meaning they migrate up to lay eggs in freshwater, but live most of their life in the sea. They aren't particularly endangered, because again, commercial fisheries avoid them. (Though, if I remember correctly, a population of them was threatened for a bit.) In combination with ppl not wanting to eat smth called "chum", causing a lower commercial value, these fellers are pretty resilient to whirling disease. (That's a parasite that affects salmonids, might post about it eventually.)