Longfin Clownfish no head deformities?

[ThRoewer]

Recently, at an LFS, I noticed something interesting about the longfin clownfish: none of them had the typical "mops-face" head deformities (short upper jaw) you generally see at least to some degree with normal captive-bred anemonefish or designer clowns.
It's the same with the two DD has right now for sale: no short upper jaw or short faces, but rather the opposite:

Maybe this could point towards the cause of the head deformities?

 

[OrionN]

The head and dorsal fin look beautiful on this fish. Just like WC IMO.

 

[D-Nak]

I've noticed less deformities with Ocellaris in general, particularly the dorsal fin. Most captive-bred Percula have rounded and shorter dorsal fins.

 

[phender]

In my experience as a breeder, the head deformities,(short faces, flared gills, etc.) were all water quality related.
As soon as I started doing daily water changes all my head deformities and 99% of my mis-bars went away.