The Yellowtails are the coolest fish in the Kelp Forest Exhibit. Not only are they my favorite sashimi fish and great fighting on the rod, but they're also fun to watch under water. They cruise around like a pack of attack submarines, and the bait fish try to keep as far away from them as possible.
Oftentimes, the other fish will use this to their advantage and snag an Anchovy that's broken formation with the rest of the school and preoccupied with watching the Yellowtail. Many a Rockfish has gotten its lunch in said fashion, thanks to the Yellowtail.
On this day, one of the 'tails was chasing a Leopard Shark, that was three times it's size, around the exhibit. It kept on rubbing against the shark, and despite trying its hardest, the shark was unable to run away.
I wonder if it was using the shark as a back scratcher, to dislodge parasites, or asserting its dominance as king of the exhibit. Maybe it was a bit of both.