Boa Constrictor

The Anerythristic (Anery) locus eliminates erythrophore (red pigment cell) function, removing red and orange coloration. Homozygous animals display striking black, white, and gray pattern with the saddle pattern retained in grayscale. Yellow tail region is common and expected. Foundational for Ghost (Anery + Hypo) and Snow (Kahl Albino + Anery).

ID tips: Anerythristic (anery/anery): Black and silver/gray pattern replacing normal brown and orange. Tail region often retains yellow wash — normal and expected. Eyes dark, normal-appearing. Hets appear phenotypically normal.

The Arabesque locus is a recessive trait that produces a distinctive modified patterning. Homozygous animals display an intricate ring-like or swirling pattern replacing the normal solid saddles. Named for its resemblance to decorative arabesque art. Discovered by Doug Dix. Maintained by specialist breeders.

ID tips: Arabesque (arabesque/arabesque): Open swirling ring-like or interlocking pattern replacing normal solid saddles. Pattern takes on an ornamental quality. Hets appear phenotypically normal.

The Blood locus is an incomplete dominant trait that dramatically intensifies red and orange pigmentation while simultaneously reducing the dorsal pattern. Three phenotypes: wild type (normal), heterozygous Blood (enhanced red/orange, reduced pattern contrast), homozygous Super Blood (extremely intensified color, pattern heavily reduced or nearly absent).

ID tips: Blood (Bl): Richer more saturated red and orange than normal. Saddle pattern remains but with reduced contrast. Super Blood (Bl/Bl): Dramatically intensified red/orange approaching near-solid in some individuals. Pattern substantially reduced.

The Central American Albino locus is the third confirmed independent albino locus in Boa constrictor. Amelanistic with orange/yellow-on-white coloration and pink to red eyes. Confirmed non-allelic with both Kahl and Sharp by complementation testing. Least common of the three boa albino strains.

ID tips: Central American Albino (ca/ca): Visually indistinguishable from Kahl or Sharp Albino by appearance alone. Definitive strain ID requires complementation testing. Hets appear phenotypically normal.

The Hypomelanistic (Hypo) locus is a recessive trait that reduces melanin production, producing an animal with lighter, more washed-out coloration. Homozygous Hypo animals retain full color palette but with reduced dark brown and black melanin. Foundational for Sunglow (Kahl Albino + Hypo) and Ghost (Anery + Hypo).

ID tips: Hypomelanistic (hypo/hypo): Lighter cleaner appearance. Dark saddle areas softened from dark brown/black to tan/medium brown. Background lighter. Orange and red tones enhanced by contrast. Hets appear phenotypically normal.

The IMG (Increasing Melanin Gene) locus is an incomplete dominant trait that progressively increases melanin deposition throughout the animal's life. Three phenotypes: wild type (normal), IMG (progressive darkening with each shed), Super IMG (dramatically accelerated progressive darkening). Originated from Boa constrictor constrictor lines.

ID tips: IMG (single copy): Progressive darkening with each shed — observe over 6-12 months. Super IMG (IMG/IMG): Dramatically accelerated darkening; adults can appear nearly solid dark with pattern largely obscured. Full phenotype best assessed at 2+ years.

The Jungle locus is an incomplete dominant trait producing aberrant (irregular, distorted) patterning. Three phenotypes: wild type (normal symmetrical saddle pattern), Jungle (aberrant irregular saddles), Super Jungle (dramatically aberrant, approaching near-patternless). No two Jungle boas are patterned identically.

ID tips: Jungle (J): Irregular aberrant saddle pattern — misaligned, fused, split, or distorted saddles. Expression varies widely. Super Jungle (J/J): Dramatically aberrant pattern, often nearly patternless or heavily fragmented.

The Kahl Albino locus is one of three confirmed independent albino loci in Boa constrictor, each proven non-allelic through complementation testing. Homozygous Kahl Albino animals are amelanistic with vivid orange and yellow pattern on a white background. Eyes are pink to ruby-red. The most common albino strain, foundational for Sunglow (Kahl + Hypo) and Snow (Kahl + Anery).

ID tips: Kahl Albino (kahl/kahl): Striking orange and yellow pattern on bright white background. No brown or black pigment. Eyes pink to ruby-red. Hets appear phenotypically normal.

The Leopard locus is an incomplete dominant trait that reduces and fragments the dorsal saddle pattern. Three phenotypes: wild type (normal connected saddles), Leopard (fragmented spot-like pattern), Super Leopard (very heavily reduced patterning, nearly absent in some individuals).

ID tips: Leopard (Lp): Fragmented spot-like dorsal pattern, smaller and more numerous than normal. Super Leopard (Lp/Lp): Very heavily reduced patterning, heavily speckled or nearly absent.

The Motley locus is a recessive trait producing a modified and connected saddle pattern. Homozygous Motley animals display saddles that merge laterally into a connected dorsal stripe or chain-link pattern with reduced pattern contrast. Distinct from Motley in corn snakes (not the same gene). Hets appear phenotypically normal.

ID tips: Motley (motley/motley): Connected chain-link or stripe-like dorsal pattern. Saddles merge into a continuous or semi-continuous dorsal chain. Lateral spotting reduced or incorporated into dorsal pattern. Cleaner streamlined appearance.

The Sharp Albino locus is one of three confirmed independent albino loci in Boa constrictor. Like Kahl Albino, homozygous animals are amelanistic with orange/yellow-on-white pattern and pink to red eyes. Confirmed non-allelic with Kahl and CA by complementation testing.

ID tips: Sharp Albino (sharp/sharp): Orange and yellow on white with pink to red eyes. Some lines show a subtle lavender cast in white areas. Definitive strain ID requires complementation breeding. Hets appear phenotypically normal.