how do various cichlids signal their fry?

I'm curious about this... I know that krib fry is attracted to the red
belly of their parent and stop moving as soon as that belly is out of
sight, but observing my severums I wonder how those fish signal their fry.
it'd be nice to have a list here of observations of parents handling their
fry, signal analyis and so on. the severum parents constantly have a
yellow bottom, but I haven't noticed any tendency of the fry to be
swimming towards it yet. I believe that the parent which is with the fry
has a brighter eye than the other one, but that could be coincidence.

let's hear it !