Now this I haven't heard of before... I can see scale less corn snakes getting the same 'love/hate' views as the derma-ball did a few years ago in the ball python forum.
Its hard to say if the scaleless gene is a negative genetic defect, but pretty much all the color morph would be considered 'negative' in the wild..a snow white corn snake stands out really well in the fading light and dark to flying birds...
Sphinx cats have been an acceptable pet for decades, as have hairless mice, rats, guinea pigs, and dogs. They do have special needs, (can get chills faster, skin more easily damaged by claws of cage mates, etc) but I really don't see scaleless reptiles being less likely to catch the interest of hobbyists and pet owners.
Scaleless bearded dragons are being developed...I don't particularly like them myself...I just find the main appeal of a bearded dragon is the variation of scales they have.
The derma-ball pictures were quite fascinating...the head and most of the top of the body was completely lacking scales, but the stomach and sides did have scales, with a scattering of almost bead like scales on the sides. It looked almost like beads..the coloration and pattern was very much normal looking. It hunted and ate food fine as well, even though it lacked the 'pits' along the upper jaw, since the scales are missing...but the sensor cells are not in the scales, so it wouldn't have its main hunting methods hindered..(though range or accuracy may have been effected...no way to tell unless researched). As corns don't use heat pits, don't see this being an issue with them.
Thus, I don't consider scaleless by itself a real difference for snakes than fur in other animals. If it hinders its natural ability to move and hunt, then it will be more of a hindering mutation. As part of the way snakes move relies on the belly scales (they can actually 'grip' with their belly scales and the way they are aligned, helps prevent backward slippage) they may have a very hard time moving without them...that will be my main concern about a totally scaleless snake.
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PHLdyPayne