A rarely seen deep sea fish resembling a serpent was found floating dead on the ocean surface off the San Diego coast and was brought ashore for study, marine experts said.The silvery, 12-foot-long oarfish was found last weekend by a group of snorkelers and kayakers in La Jolla Cove, north of downtown San Diego, the Scripps Institution of Oceanography said in a statement.It's only the 20th time an oarfish is known to have washed up in California since 1901, according to institution fish expert Ben Frable. Scripps noted that oarfish have a mythical reputation as predictors of natural disasters or earthquakes, although no correlation has been proven. Oarfish can grow longer than 20 feet and normally live in a deep part of the ocean called the mesopelagic zone, where light cannot reach, according to the National Oceanic and Atmospheric Administration.Swimmers brought the La Jolla Cove oarfish to shore atop a paddleboard. It was then transferred to the bed of a pickup truck.Scientists from NOAA Southwest Fisheries Science Center and Scripps planned a necropsy on Friday to try to determine the cause of death.