For the second time within just a week, an oarfish carcass has appeared on a southern California beach.

The long, sea serpent-like fish is rarely seen by humans, so the double sighting has been a cause of excitement in the scientific world. The oarfish that washed up on an Oceanside beach on Friday was 13 1/2 feet long and the one that was found on Catalina Island last week was 18 feet long, one of the largest seen in the last 20 years.

The more recent oarfish washed up on one of Oceanside’s jetties on Friday, and up to 75 people crowded around to get a look at it before they called police. According to UT San Diego, one of the people who called police told them that he thought it was a whale.

"It's so rare to find in Southern California, especially in surface water," Suzanne Kohin from the National Marine Fisheries Service said, reports ABC News. "They thought it was a very rare event the first time, so these two events that we heard of in the last few weeks are the only ones I've ever heard of."

SeaWorld San Diego, The Scripps Research Institute and the National Oceanic and Atmospheric Administration were all contacted by police to come and retrieve the carcass from the beach. A woman from the NOAA responded and arrived to measure the fish before it was cut into pieces and put into coolers to be taken away for further study.

The oarfish will be dissected on Monday by experts in marine biology, according to the New York Daily News. They are most interested to view the contents of its stomach, to see what the diet of an oarfish consists of.

Little is known about oarfish except that they can grow as long as 50 feet and that they typically live deep within the ocean, at about 3,000 feet below the surface.

Image courtesy of Wikimedia Commons