Reptile & Amphibian Forums

Ok, I should probably know this already, but I cant seem to figure out how they determine the het percentage (say with albino's for example), and also the likelyhood of attaining (albanism) in the offspring. I know an albino bred to a normal, the normals will be 100% het, but beyond that it gets a little sketchy. Any help is greatly appreciated!

Statistically speaking, crossing albino x het gets 50% albino & 50% het. Het x Het gets 25% albino, 50% het and 25% normal. These are generalities, and are the statistical chance that any 1 individual will express the particular trait, in this case albinism.

I am assuming you aren't asking about how to produce hets, but about what the percentages you see listed on price sheets mean.

The whole thing about being "100% het" vs "66% het" vs "50% het" is misleading. Snakes either are hets or they aren't. They can't be partially heterozygous.

What these percentages are saying is that the snake has that probability of being heterozygous.

It comes about like this -

If you breed an albino to a normal all the babies will appear normal, but they will all be hets. Therefore, people will say that they are 100% hets (guaranteed heterozygous)

If you breed a het to a het, then 25% of the babies should be albino, and the other 75% will be normal looking. Of those normal looking snakes, 2/3 (66%) should be heterozygous. But there is no way of telling by looking at them. The only thing you can say for sure is that any normal individual has a 66% chance of being heterozygous. Those are sold as "66% hets". So 1/3 of all 66% hets aren't hets at all.

If you breed a het to a normal you will get all normal looking offspring. But half of those normal offspring will be heterozygous. So therefore any of the offspring has a 50% chance of being heterozygous. So no individual is 50% heterozygous, each one simply has a 1/2 chance of being heterozygous.
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Chris Harrison
Central Texas