What defining characteristic separates the highly priced Golden Cross Back Asian Arowana from the Red Tail Golden?

The gold color on the Golden Cross Back completely crosses its back when matured, whereas the Red Tail Golden coloration stops at the fourth or fifth row of scales

Within the coveted category of Asian Arowanas, subtle variations in scale coloration dictate immense differences in scarcity and price. The Golden Cross Back variety, originating from West Malaysia, is prized specifically because its distinctive gold pigmentation fully develops to extend across the entirety of its dorsal surface when the fish reaches full maturity under ideal conditions. This complete dorsal coverage is the hallmark differentiating it from the Red Tail Golden. The Red Tail Golden, a more accessible option, develops shiny gold scales, but this coloration is restricted, typically terminating before reaching the midline, stopping at the fourth or fifth row of scales from the lateral line, thus failing to complete the 'cross back' pattern.