All Angles Creatures

Anerythristic Type I Anerythristic Type II Red-Tailed Boa Constrictor

One animal carrying both genes. Each one is inherited separately, so this combination is made by bringing them together rather than being a gene of its own.

The two genes

Anerythristic Type I
recessive
Red and orange pigment absent, leaving a grey, brown and black animal.
Anerythristic Type II
recessive
A separate anerythristic line, often browner than Type I and holding more pattern.

How one is made

Both genes have to come together in the same animal. The pairing that does it most directly is Anerythristic Type I × Anerythristic Type II, which works out every outcome and its odds.

Worth knowing

Anerythristic Type I. As with the albinos, there is more than one anerythristic line. Type I and Type II are different genes and pairing them produces no anerythristic young.

Every Red-Tailed Boa Constrictor combination