The raised lines(like fins) on the body you mention are tiny loose folds of skin from it being totally emaciated. They probably never ate most of their lives, and especially at the freakin Petco!.
Most pet stores like that don't give too craps if their snakes die or not. And most of the employeees that work at those places know next to nothing about proper snake husbandry either, so it's a horrible combination to be honest. The snakes are there strictly to be SOLD, not cared for at all.
It's a sad fact............but a fact nonetheless.
I feel bad for lots of neglected animals in pet stores, and I know it is sometimes human nature to want to take animals in that don't seem to have a very good life in these stores. But my advice is to never buy a snake that has loose folds(ridges) along the sides of it's body, because that means something is very wrong.......either because of the store, or it is doing poorly anyway. I see so many poor looking snakes and lizards in pet stores it is absolutely ridiculous!. And if snakes and lizards had fluffy fur and big brown eyes instead of scales, these stores would be out on their ear before you could count to ten. But most of the general public doesn't view reptiles like they would more common warm-blooded pet animals. :shrugs:
~Doug
