Mean_Chlorine wrote in
:

http://lindamar02.tripod.com/fat_SAE/

So... It may be you've got obese SAE's, yes.

Yes, I second that.

Had it been another fish I'd have suggested it might be a gravid
female, but SAE's rarely if ever spawn in home aquaria, so that seems
unlikely.

Well, that isn't actually so rare. They do spawn, and even when they don't,
they can get filled with eggs. The fatter fish might be a female belly full
of eggs - and fat, too. Give them LOTS of water movement, do a huge water
change and drop the temp with 1-3 degrees (C) and see what happens. If you
see them dancing with high heads and faded side stripes, they might thing
of laying eggs.

Liisa