loaches belly markings

[helen nightingale]

i have been wondering. after spending ages peering into my tank trying to tell the differences between some new little striata, i reckon that my older loaches have much more bold belly markings than the medium loaches. and the babies seem to have quite pale bellies. does this have any resemblance to maturity of the fish? or just how wide its belly is?

[sophie]

veering wildly away from striatas,
my yoyos are divided between the ones that still say "yoyo" and and the ones that don't (and never really did), and the ones with pale bellies and the ones with markings.
they're all the same age.
and I don't think it's a gender thing, either...

maybe they just have variable bellies?