A rare fish whose ancestors probably inspired legends of sea serpents in the ocean’s murky depths has washed up on the coast of southern California, which has become something of a repository for the carcasses in recent years.

The dead 17ft-long oarfish discovered on Monday on Santa Catalina island has inspired curious locals to visit the beach to see the carcass and take smiling photos alongside it. Because the species resides in the deep sea, typically depths between 700 and 3,000ft, it is rare to spot them on the surface.

“I’ve lived on the island for over 20 years, and I’m on the water all the time … and I’ve never seen one,” Annie MacAulay, founder of the educational nonprofit Mountain and Sea Adventures, told ABC7.

There was evidence that seagulls had feasted on the body of the oarfish, which was found by the island harbor patrol. It is not known how it died. Scientists conducted a necropsy on the fish before transporting it to researchers at California State University, Fullerton.

Catalina Conservancy (@CIConservancy) Giant #oarfish found on Catalina yesterday! http://t.co/doYd6LDO26 pic.twitter.com/cY7tt3hSg4

In 2013, two oarfish were found on the coast of southern California in the span of a week. One of the fish was found floundering in shallow water before it died. The other was discovered, dead, by a group of third graders. “I was thinking I have no idea what that is and like it looks like a snake, but it kind of looks like a giant eel,” Alexandria Boyle, one of the students who discovered it, told KGTV in 2013.

Oarfish can grow to be 50ft long and have been spotted across the ocean, except in the polar seas. They are not good for eating, because of the “poor quality of meat which is gelatinous and generally considered inedible”, according to the University of Florida’s department of ichthyology.