When Jim Byrne was trout fishing in South Puget Sound, he spotted an unusual sight.

Byrne saw an ocean sunfish (Mola Mola), which averages between 545 and 2,205 pounds as an adult, according to Washington Department of Fish and Wildlife fish biologist James Losee.

The Mola Mola is one of the heaviest known bony fishes in the world, and can reach up to six feet long. It is also a major jellyfish eater.

The fish is known to frequent southern, warm water masses in the open ocean. It is rarely seen in places like Squaxin Passage, where Byrne saw his Mola Mola.

There have been several Mola Mola sightings near Tacoma and Olympia in the last 10 years, according to zoologist Tierney Thys.