Swordtail

representative

Green Swordtail (wild-type) →

The wild-type Xiphophorus hellerii: an olive-green body with a fine red lateral stripe and a long sword extension on the lower caudal fin of males.

Tip: The hardiest form — provide hard, slightly alkaline water (pH ~7.5+, GH 12+) and a tight lid, as swordtails are notorious jumpers.

representative

Green (wild-type) →

The natural Xiphophorus hellerii: olive-green flanks with a red lateral stripe and, in males, the long lower 'sword' tail extension.

Tip: Active and a strong jumper — keep a tight-fitting lid. Hard, neutral-to-alkaline water and room to swim (90 L+).

Red Swordtail →

The ubiquitous solid red-orange line developed through selective breeding (often with platy introgression) for full-body red coloration.

Tip: Color stays richest with a varied diet including natural carotenoids (spirulina, krill); keep one male to several females to reduce harassment.

representative

Pineapple / Marigold Swordtail →

A bred line with a yellow-to-orange gradient body — pale yellow head shading into orange toward the tail, like ripe marigold or pineapple.

Tip: The yellow ground shows fin damage and disease (fungus, fin rot) readily, so it's a good early-warning fish — keep water pristine to preserve the clean gradient.

Lyretail Swordtail →

A finnage mutation that extends the top and bottom caudal rays into trailing lyre points; available over most color lines.

Tip: Lyretail males have elongated gonopodia that can impair fertilization — keep dedicated short-finned males in the colony if you need reliable breeding.

representative

Wagtail / Tuxedo Swordtail →

Wagtail adds solid black fins and lips to a colored (usually red) body; tuxedo adds a black flank blotch — both fixed pigment patterns from selective breeding.

Tip: The melanin-heavy tuxedo lines are slightly prone to melanoma when over-bred for black, so source from reputable lines and don't intensify black beyond the standard pattern.

representative

Red Velvet →

Solid deep-red body and sword, the most familiar fancy swordtail.

Tip: Standard swordtail care; colour holds well on a varied diet.

representative

Pineapple / Marigold →

Yellow-orange body grading toward a red sword and dorsal.

Tip: Standard care.

representative

Koi (Kohaku) →

White body with red-orange blotches echoing koi carp patterning.

Tip: Standard swordtail care; pattern varies fish to fish, so hand-pick for the look you want.

representative

Lyretail →

Both tail lobes extended into trailing points; males' modified gonopodium can impair breeding.

Tip: Keep with gentle tankmates to protect the finnage; lyretail males may breed poorly, so keep standard-finned males if you want fry.