The ocean sunfish (Mola mola) is the largest of all bony fishes and can reach an astonishing 3,000 pounds or more; the world record is 5,071 pounds. These gentle giants are also hugely popular with Aquarium visitors.

 Aquarist target feeds an ocean sunfish, from the catwalk over the Outer Bay exhibit

Although we've successfully displayed ocean sunfish for more than 20 years, their lives in the wild are shrouded in mystery. In 2008, we undertook a research collaboration to more thoroughly study ocean sunfish in Monterey Bay. We know that they are seasonal visitors to bay waters, but where do they travel when they leave? Do the same animals return annually? What do they eat? How deep do they dive? Through a program of tagging and tracking via satellite, coupled with genetic analyses, we're trying to find answers to these and many other questions about these bizarre and intriguing fish.