For many years, I held a weekly feeding session for the resident reef sharks and their visitors in the study area where I observed their behaviour. If I had enough shark food, I would scatter crumbs into the water for the fish after the sharks had left. The fish knew this, so they had to wait, and while they were waiting, they were excited.
As the session wore on and darkness fell, they gathered. They would creep ever closer as the moment I would feed them approached. The surface glimmered with the continually circling needlefish, who looked at me gravely with their big eyes.