Question

Why do fish go in deep waters during day light?

Answer 1

During day time, the shallow water is warmer and hence contains less dissolved oxygen. Therefore fish tend to go in deep water during day time.

Answer 2

For this reason, fish goes deeper in the water where the oxygen content is higher. The shallow water is warmer during the day due to which it has less dissolved oxygen. So the fish tend to go in deep water during the day time.