Do fish sleep on water?If yes then how?

While fish do not sleep in the same way that land mammals sleep, most fish do rest.

Research shows that fish may reduce their activity and metabolism while remaining alert to danger. Some fish float in place, some wedge themselves into a secure spot in the mud or coral, and some even locate a suitable nest

because they are eaten by the frog and the frog getseaten by the snake and the snake by the eagle