Hi Clint –
The “white undercolor” is part of your snake’s epidermis, as are the scales. Let’s just call it skin. Perhaps you’ve noticed how stretched the skin becomes when your snake eats a particularly large meal. But then the swelling goes down as the meal is digested and the scales are able to overlap again. Many things inside a snake’s body can cause swelling which does not subside – embryos (not in your case), an enlarged heart, a tumor, an abcess, just to name a few. But I would guess that what you are seeing in the photos and your snake is the result of too much excess adipose tissue. Or, to put it less delicately – those snakes are overweight.
I’m not saying that snakes in the wild don’t naturally gorge themselves sometimes. Seasonal availability of prey, getting ready for brumation or hibernation or the breeding season – all these situations may produce temporarily “fat” animals. Snakes store their excess fat as fat bodies in their body cavities for use during leaner times. Thing is, in captivity, the lean times never come. Hobbyists buy hatchlings and feed them a constant abnormal amount of food in an attempt to grow them up as soon as possible, or just out of a sense of “caring”.
I don’t know if your snake is really overweight, Clint. And I think I used your question unfairly for a mini-rant here. But many of the photos of prized juveniles and adults you see on these forums share this characteristic to some extent, as indicated by small heads which haven't "caught up" to the body size yet, and scales which are unable to overlap. Is this a bad thing? Time will tell as the hobby matures. No, snakes aren’t mammals, but I don’t think it is too much of a stretch to believe that we are causing health problems and shortened life spans for these captive reptiles by feeding them far more than they would normally require.
-Joan
>>I have an adult male BP and have noticed over time his scales seperating a bit and his white undercolor showing through. I'm sure this is normal because ive seen plenty of pics showing this. I would just like to know what causes it. It's not so much as he has lost scales, but just kind of looks a little diferent. Please shed some light. Thanks.
>>~Clint