World's second largest fish

A basking shark

A basking shark the world's second largest fish tagged with a tracking device in June 2011 suddenly checked in near Hawaii after eight months of silence, researchers reported this week. The fish, tagged near San Diego, was one of only four basking sharks ever tagged in the eastern Pacific, and the lone shark to keep its tag for such a long time.
Basking sharks, the second-largest fish on the planet, were once plentiful along the Pacific coast of North America, gathering by the hundreds and even the thousands. Now, it's a rare treat to see even one of these ocean giants. Yet within the space of just a few days, satellite technology has offered scientists an unprecedented look at the mysterious wanderings of this elusive fish.

Source: Live Science