Question

When scientist need to work on Sharks and some other fish in water they flip them upside down on their backs because

Answer 1

In simple words, Sharks have the ability to enter a trance state. Whenever a shark is flipped upside around it enters a trance-like experience known as tonic immobilization.

That's why, when certain researchers are operating on saw fish with in ocean, they often turn them over. Otherwise, there is a chance that the fish might start panicking and the work of scientist will get tougher.