Swordtail

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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.

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.

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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.

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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.