GRANTS PASS, Ore. >> A fish normally found in the ocean off Japan and other tropical waters has turned up alive in a crab pot hauled up by a fisherman off the Oregon coast.

It’s possible the fish — a striped knifejaw — came across the Pacific in debris from the 2011 Japanese tsunami, said John Chapman, an invasive species specialist at Oregon State University’s Hatfield Marine Science Center in Newport. Other possibilities include the fish being discharged from a ship’s ballast, or being dumped from an aquarium.

This is only the second confirmed discovery of a striped kinifejaw on the West Coast, Chapman said. The other was March 2013, when five striped knifejaws were found alive near Long Beach, Washington, in a boat that had drifted over from Japan. Four were killed, and the fifth put in an aquarium for display.

The new fish, found off Port Orford, is 5 inches long, shaped like a sunfish, with black and white stripes. It was taken to the Hatfield Center in Newport, where a veterinarian was ready to treat it for cuts on its belly, Chapman said.

It was lucky the fisherman who found the fish recognized it as an exotic, put it in a well on his boat, and turned it over to the university, said John Calvanese, an OSU graduate student working at a field station in Port Orford.

An estimated 300 different invasive species have drifted across the Pacific on tsunamis debris, Chapman said. Most are small invertebrates. Many are unidentifiable, either because they are in a stage of life not recognized by scientists, or they are new to science.

“Debris is still coming across the ocean,” Chapman said. “We know there is this conveyor of species from Asia land on our shores. We’ve found parasites inside mussels that came across, mussels themselves that are strange, and oysters with parasites that have never been seen before, even in Asia. We’re worried.”