Axolotl morph
Axolotl (Ambystoma mexicanum)
Homozygous recessive at the Melanoid locus (m/m). Iridophores are completely absent, and some xanthophores convert to melanophores, resulting in increased dark pigmentation and reduced yellow. The overall appearance is uniformly dark gray to jet black with a matte finish. No iridescent speckling. Gills and eyes are dark. The lack of iridophores is the key distinguishing feature from dark wild types, which retain shiny speckles. Melanoid is one of the most popular morphs for hobbyists who prefer a dramatic all-dark animal. Genotype: D/- A/- m/m Ax/- Cu/-.
The Melanoid locus controls iridophore differentiation. Homozygous recessive (m/m) animals lack iridophores entirely, which eliminates the shiny/iridescent speckling seen in wild type axolotls. The absence of iridophores also triggers a secondary effect: some xanthophores convert to melanophores, resulting in increased eumelanin deposition and reduced yellow pigment. The net effect is a uniformly dark gray to jet black animal with no iridescent highlights and minimal yellow. Melanoid is one of the most visually striking axolotl morphs.
How to identify it: Melanoid (m/m): Uniformly dark gray to jet black. No iridescent/shiny speckling anywhere on body (key distinguishing feature from dark wild types). Reduced yellow pigment compared to wild type. Gills are dark. Eyes are dark. Body has a matte finish rather than the slight sheen of wild types. Carriers (M/m) are visually indistinguishable from M/M wild types.
Melanoid follows a recessive inheritance pattern, carried on the Melanoid allele (locus Melanoid).
Because Melanoid is recessive, an animal needs two copies of the allele to show the trait visually. An animal with a single copy is called het melanoid (heterozygous). A het animal looks normal but carries the gene, so pairing two het melanoid animals produces, on average, one in four visual melanoid offspring.
Melanoid Copper
Double homozygous for Melanoid (m/m) and Copper (cu/cu). Melanoid removes iridophores and increases melanophore density; copper converts eumelanin to pheomelanin. The result is a uniformly dark brown animal with a matte finish. Like a melanoid but brown instead of black. No iridescent speckling.
Melanoid Axanthic Copper (MAC)
Triple homozygous recessive for Melanoid (m/m), Axanthic (ax/ax), and Copper (cu/cu). One of the most sought-after and expensive axolotl morphs. Melanoid removes iridophores, axanthic removes yellow pigment, and copper converts eumelanin to pheomelanin (brown). The net result is a unique lavender to purple-gray animal with a smooth, matte appearance. The lavender coloration arises because the copper-derived brown pigment, without yellow or iridescent interference, appears as a soft purple-lavender tone.
Melanoid Albino
Double homozygous for Melanoid (m/m) and Albino (a/a). The melanoid mutation removes iridophores, and the albino mutation removes melanin. The combination produces a pale yellow to cream animal with no iridescence and no dark pigment. Eyes are pink/red. Less visually distinct than either single mutation because both major pigment types are reduced. Primarily xanthophore (yellow) coloration remains.
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