I want to talk about something that’s been bugging me: leucism is a genuinely weird morph.
“Weird how?” — yeah, that’s the reaction. Let me lay out what actually trips me up:
- How it differs from albino
- It shows up mostly as a super form, yet as a single-gene morph it isn’t really a “whitening” morph at all
- The ways it gets produced are all over the place
Let me walk through these one at a time.
① Leucistic vs Albino — What’s Actually Different
On paper, albino is a lack of melanin — the black pigment disappears or gets reduced. Depending on whether the animal produces tyrosinase (the enzyme that makes melanin), you get T+ or T− albinos, but either way it’s fundamentally a “black drops out” morph.
Leucism is different. It’s a whitening effect — the animal turns white — but the melanin (the black pigment) is still there. That’s why you end up with a snake that has black eyes but a white body.
“So why are you even comparing two different things?” Fair. Here’s why: in reptiles, albinos are easy to spot because the yellow and red pigments stick around. But in mammals and some other animals, telling albino and leucistic apart is apparently a nightmare.
…yeah, good luck telling those apart. 🫠
② As a Single Gene, It Isn’t Even a Whitening Morph
Here’s the part that really gets me. Take ball pythons: breed Russo × Russo and the super form, Super Russo, is a leucistic morph called “White Diamond.”
But a single Russo? It looks like this:
And the super form? This:
Like… what? 😂
The super form clearly isn’t just an extension of what the single-gene morph is doing. With a co-dominant morph like Pastel, I can wrap my head around it — Super Pastel reads as “Pastel, but cranked up.” Leucism? No such logic. It just does its own thing.
③ The Ways It Shows Up Are All Over the Place
Just within ball pythons, leucism can come out of any of these:
- Super Russo
- Super Mojave
- Super Lesser
- Piebald Spider
And it doesn’t stop there. Super Black Pastel crossed with albino can do it; Yellow Belly and Orange Belly supers apparently whiten out as they mature from hatchling to adult.
For carpet pythons, the only route I know of is Super Jaguar — which is very often lethal.
Then there’s stuff like the bearded dragon “Zero,” which sure looks like a whitening morph… except Zero is a plain recessive, so it isn’t technically leucistic. Still, the effect looks like whitening to me.
So yeah — leucism is a genuinely weird morph. That was the whole point I wanted to make.
Catch you next time.