Short body is a mutation, there can be any number of these deformed individuals, and other types of deformities in a normal cichlid spawn. In nature survival of the fittest usually weeds them out.
But if two of these deformed individuals are bred together , more are produced, a mutated line can be "fixed".
Just like blood parrots were created by breeding together certain mutations together, they are not a real species.
Back in the old days, any of these would have been culled by responsible fish breeders. to keep the integrity of the species.
Can you tell by my response, I find this kind of mutant propensity abhorrent?
And makes the new cichlid fad no different than balloon goldfish.