Why does fish curl up when deep frying?

Chef's answer
if you use wet batter, dry the meat first with paper towel and news papers. if you leave skin on, one side will stay longer than the other and make it curl up. 3 minutes is all it needs in hot oil no matter what method you use, pan or fryer. sounds like its too hot to me too or too long, one or the other or both.
Frequently asked Questions 🎓
As the bacon cooks the meat reduces in size faster than the fat does. Since they are cut into strips this causes the fat to bunch up or even coil if the bacon isn't flipped enough. The fat will eventually reduce as well when it renders but not enough to straighten out the poor bacon.
When it starts looking like it's going to curl, flip them over and cook the second side how you want the finished product. After flip them again to finish cooking the first side. Make three or four lengthwise cuts in the PS before slicing. This helps reduce the curling..
You can sear them skin side down then when you turn them over gently poach them. With how small they sound the entire cooking process should only be about two to three minutes long at most. Not even getting that far. I put them in the pan skin-side down, but they're curling immediately..
Lobster tails tend to curl as they cook. To avoid this, insert a skewer through the tail before baking or broiling, then remove it before serving. Lobster meat turns rubbery and tough when overcooked..
As a lobster is cooked, the tail meat naturally wants to contract and curl.
Most of the time, bacon will come out flat and browned and beautiful just like that. If you have particularly thin or fatty pieces of bacon, however, it can still curl up on you as the water evaporates from the meat and the belly fat renders. To combat this, simply lay another wire rack face-down on top of the bacon.
As the bacon cooks the meat reduces in size faster than the fat does. Since they are cut into strips this causes the fat to bunch up or even coil if the bacon isn't flipped enough. The fat will eventually reduce as well when it renders but not enough to straighten out the poor bacon.
A few more cooking questions 📍