Riardi Genetic Codex- Riumae-Specific Traits

The Riumae body type carries a unique genetic suite derived from merfolk ancestry, focusing on aquatic adaptations. These traits are dormant in other Riardi lineages.

Dorsal Adaptations- FRW, SKR, RSF Loci

These loci dictate the presence of fins and spines along the spine.

Locus	Genotype	Phenotype
FRW (Fin Rows)	FRW/FRW	3 full dorsal fin rows
	FRW/frw	1-2 fin rows
	frw/frw	No visible fin rows
SKR (Spike Rows)	SKR/SKR	3 rows of spikes
	Skr/skr	1-2 rows of spikes
	skr/skr	No visible spikes
RSF (Spiked Fin)	RSF/RSF	All dorsal fins are spiked
	RSF/rsf	Mixed: some smooth, some spiked
	rsf/rsf	Smooth fins (default)

Head & Facial Adaptations- SCF, BRB Loci

These modify the riumae's head structure to reflect their orumae heritage.

Locus	Genotype	Phenotype
SCF (Scaled Face)	SCF/SCF	Fully scaled scalp and nasal bridge
	SCF/scf	Partial scale coverage
	scf/scf	Smooth skin (default)
BRB (Barbels)	BRB/BRB	Full set (4-6 long tendrils)
	BRB/brb	1-2 short barbels
	brb/brb	Standard whiskers (default)

Hairlessness (HR Locus)

The HR locus dictates follicular density. While it can appear as a spontaneous mutation in any riardi, it is highly concentrated in the riumae lineage.

Genotype	Expression
HR/- (Heterozygous)	Thin/patchy fur; reduced whiskers. Carrier of hairlessness.
HR/HR (Homozygous)	Fully hairless/peach-fuzz. Scalp hair max jaw-length.

Interactions

Double-coated (Rithi Hybrids): HR/- results in sparse, extremely soft undercoat.
Satin/Metallic (Opal/Ore): HR/- retains sheen despite thin hair.
Frizzle (Central Hybrids): HR/- results in sparse, wiry, patchy fur; HR/HR results in total hairlessness.
Guard Hair Defect: Combined with HR, this leads to near-total baldness, even in heterozygous HR/- individuals.

Integration Notes

Conditional Expression: These traits remain latent in non-riumae riardi. If a cross-breed occurs, the presence of the riumae body-type gene is the "key" that unlocks the expression of the FRW, SKR, RSF, SCF, and BRB loci.
Temperature Regulation: Individuals with HR/HR genotypes require active temperature regulation, as they lack the insulating protective coat of standard riardi.