Anerythristic (Type 1) Boa Constrictors
A Type 1 anerythristic boa loses its red but keeps yellow and black, so the saddle pattern shows in grey and black rather than tan and orange. It has been proven incompatible with both Type 2 and Carbon, so check which type each animal carries before pairing two anerys.
Other Anerythristic strains
About the Anerythristic (Type 1) gene
Anerythristic (Type 1) is a boa constrictor gene that removes red pigment and leaves yellow and black in place, so a visual reads grey, black, white and silver rather than the tan and orange of a normal boa. It has been proven incompatible with the separate Type 2 line and with Carbon, so pairing it with either gives no anerythristic offspring. Keepers buy it for the grey and black pattern on its own, or as the base for combination morphs such as Snow, Ghost and Moonglow.
Appearance
The boa's saddle pattern stays visible in a visual Type 1 anery, but it appears in shades of grey and black instead of warm oranges and browns. Even on an animal that is otherwise greyscale, a trace of yellow pigment typically survives in the tail.
Genetics
Because Anerythristic (Type 1) is recessive, a visual requires two copies and anything with fewer looks like a normal boa constrictor. A visual is Anerythristic (Type 1), while a proven carrier is Het Anerythristic (Type 1). A possible carrier is 66% Het Anerythristic (Type 1), 50% Het Anerythristic (Type 1) or Pos Het Anerythristic (Type 1). It does not have an allelic complex of its own. It combines with Albino and Hypomelanistic to make named morphs such as Snow, Ghost and Moonglow. Unlike the Central American Type 2 line, Type 1 is associated with Colombian boa stock. Breeding trials have proven the two are incompatible with each other. Compatibility with the Carbon line is also ruled out by a separate proof. For Type 1 itself, no originator or year is on record.