Boulengerochromis microlepis is a Tang, not hap, and is an egg layer. Only egg layers bang glass, an instinct to guard the nest and fry, never mouthbrooders. Once mating is done, mouthbrooders go separate ways. Frontosa don't bang glass, but tiny compressisep will. I am not talking about tangs, which originated from multiple bloodlines and exhibit diverse body shape, breeding habit and behavior, but not much color variation though. Haps lack diversity in shape and color, including many accidental hybrids. Only a few species out of a thousand exhibit unusual body shape, such as the Malawian trout, compressisep and Moori, and that's all.