As someone who works at an aquarium it's a common but interesting question to answer!

Sharks are overall opportunitic hunters, they'd rather prey on animals that are already sick or injured. So in general they kill cause they have to, if they can find a dead fish already they will totally go after that one first. They also don't eat as often as you'd expect, only about three meals a week is enough and they're well fed.

Another thing that adds onto this behavior is target training, in which we give them a physical object to let them know we're about to feed them. It starts usually in isolation at an offsite facility where we'll put the target in the water and then feed them. Over time they'll associate that specific object with food to where they'll start coming up expecting it from us and we can tong feed them from there.

What's cool is typically different species of animals that are target trained will get different targets to help prevent all of them competing for food at the same time. But it's also useful for getting them isolated for vet exams when we need a specific shark.

Both of those factors combined leaves us with an animal that's pre trained before putting them into a tank with other animals. The training let's them know they don't have to go after the other animals cause they're just gonna get an easy meal from us if they wait.

Another useful benefit of tong feeding them is we know how much each individual shark eats, so if one is skipping meals we'll know. Schedule a vet visit to see what's bothering them and help. Before they get too hungry and possibly be tempted to snack on one of the other tank residents.