Who performs operations in the fish hosputal?

Fish hospitals are not real places. Fish don't go to hospitals the way humans or other mammals do.

* Veterinarians specialize in treating animals, including fish. They can diagnose and treat illnesses, perform surgeries, and provide other care.

* Aquarium hobbyists may also provide basic care to their fish, such as treating infections or injuries.

So, while there are no "fish hospitals" in the traditional sense, fish do receive care from veterinarians and hobbyists.