The fish was discovered by ecologist Jessica Nielsen from the University of Goleta. She turned to a number of specialists from the US, Australia and New Zealand for help investigating the dead fish.
"This is certainly the most remarkable organism I have seen wash up on the beach in my four years at the reserve," Nielsen said in a UC Santa Barbara press release.
It turned out to be a hoodwinker sunfish that are found exclusively in the Southern Hemisphere, near the coast of Australia, New Zealand, South Africa and Chile. How it crossed the equator and ended up in California is not yet clear.
Scientists suggest that the sunfish may be a specimen of the still unexplored pack of hoodwinker living in the waters of North America.