A male fish does not have a special name for being male and is simply referred to as a fish. Unlike some animal species, there is not a gender specific name for either a male or female fish.
Fish do not have categorizing names that describe whether they are male or female. This is also true with many other sea critters such as jellyfish, frogs, eel and turtles. Fish are typically categorized by the specific type of fish that they are such as a goldfish or a sailfish. When fish are babies they are referred to as fry or fingerling.