Photo by Steve Mirick and used with his
permission.
Your first awareness of this strange creature often seen on
pelagic trips is a dark fin wobbling back and forth on the surface.
Unlike a shark or other fish it doesn't seem to move forward but
rather rocks back and forth with the waves. You are looking at an Ocean Sunfish
or Mola mola.
Closer scrutiny reveals a large flat fish with a
dorsal fin and a larger ventral or anal fin projecting downward like a
centerboard of a sail boat. There is almost no tail. It is a harmless creature
that feeds primarily on jellyfish and other small plankton. Participants on a
Southern California pelagic trip reported an Ocean Sunfish
breaching.