An Ocean Sunfish (Mola mola) swimming close to shore! Known as the heaviest bony fish in the ocean, these gentle giants are often misunderstood. Despite their impressive size, ocean sunfish are completely harmless to humans, feeding primarily on jellyfish and other gelatinous zooplankton. One of the most common misconceptions is mistaking their tall, triangular dorsal fin for that of a shark. But here's how you can tell the difference: Sunfish fins move side to side, gently flapping as they bask