The striped beakfish, which is native to Asian waters, was found alive in a small boat thought to have drifted to the US west coast after the Japanese tsunami in March 2011.
The fish was found alive in a bait box on the boat by an official from the Washington Department of Fish and Wildlife while he was examining the marine organisms on the vessel.
It is thought that it survived by eating other organisms on the boat.
The striped beakfish is now a star attraction at the Seaside Aquarium in Oregon where it is housed.
"People are pretty fascinated about seeing this fish and the fact that it came all the way over from Japan in the debris, so it has been a pretty cool event," Keith Chandler from the aquarium said.
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