Which fishes produce alarm signals to warn other group members about in coming predators
Here are some fishes produce alarm signals as sounds.

members of family Pamadasyidae-the grunts. 

the family scaridae e.g.—Parrot fish.

sea catfish Galeichthyes felis

gafftopsail catfish

Indian loach

Trigger fish

Epinephelus striatus

For mor information see the link. http://www.fishfarmingtechniques.com/fish-structure/specialized-organs/sound-producing-organs/sound-producing-organs-in-fishes-specialized-organs-fisheries/13563