These Boa constrictors are significant with lack of erythrin (yellow pigment),
they are simply called anerythristic = anerys. On the first sight they look
like from old movie, they are black and white.
Saddles of this Boa constrictor form are on grey-white ground. Tail pert is
lined by black and also tail saddles are with black speckles. Even we say
from the first description, these snakes are not interesting, but this is
only first sight. Various types are defined, that is dependant on locality
and original range.
Natural anerys are found in Columbia and Nicaragua. Anerys themselves are
very attractive, this affect multiplies the fact, that they stand in basics
color forms called ghost and snow (going for double heterozygous animals).
Albinos do really have small chance to survive, the same have ghosts…
In the nature were found natural ghosts, on that fact the human mind only
stares, when we calculate the chance of meeting parents with appropriate
genetics to create that mutation. To help the nature “complete” the started
way, decided the breeders to help the nature with selective breeding with
goal to set up the snow variant of Boa constrictor.
And it happened. Snow boas are now quiet common available.