Red Swordtail

Xiphophorus hellerii

Animalia›Chordata›Actinopterygii

Variety of Swordtail · red

📍 Central America

The most widely kept swordtail variety, featuring uniform bright red to red-orange coloration across the body, contrasted by the characteristic elongated lower caudal fin lobe in males. It is a hardy, active livebearer ideal for beginners, doing well in community tanks with hard, alkaline water and tankmates that won't nip fins.

Size4.5"

Min Tank20g

School3+

peaceful

Zonemid

Care Guide

Diet

Red Swordtails are omnivorous and should be fed high-quality flake food or small pellets as a staple, supplemented 2-3 times weekly with frozen foods like brine shrimp, bloodworms, or daphnia. Include vegetable matter such as blanched spinach or algae-based foods to support their health. Feed small amounts once daily, only what they can consume in 2-3 minutes.

Behavior

Red Swordtails are active, peaceful fish that spend most of their time in mid-water zones, though they will explore all levels of the tank. Males are territorial toward each other and will display with their characteristic sword-like tail extension, but rarely cause serious harm in adequately sized tanks. They are social and do best in groups of 3 or more, with a preference for more females than males to reduce aggression.

Breeding

Red Swordtails breed readily in captivity as livebearers, requiring no special conditions beyond adequate space and mature water. Females produce 20-100 fry every 4-6 weeks once mature; fry are born fully formed and independent. To protect fry from predation, provide dense plants like Java Moss or Water Sprite, or use a separate breeding box.

Tank Mates

Guppy

Similar size, peaceful temperament, and identical water parameter requirements make them ideal companions

excellent

Platy

Fellow livebearers with compatible behavior and water needs; can interbreed but generally coexist well

excellent

Neon Tetra

Small, peaceful schooling fish that thrive in similar water conditions and add visual interest

good

Gold Mystery Snail

Peaceful algae eater that occupies different ecological niche and poses no threat to swordtails

good

Java Fern

Hardy plant that provides shelter for fry and helps maintain water quality without being uprooted

excellent

Common Diseases

Fin Rot

Symptoms

Fraying, discoloration, or deterioration of fin edges; often starts at the sword in males

Treatment

Perform 25% water changes every 2-3 days, improve water quality, and treat with aquarium salt (1 teaspoon per 5 gallons) or antibacterial medication if severe

Ich (Ichthyophthirius)

Symptoms

White spots covering body and fins, rapid breathing, rubbing against objects

Treatment

Raise water temperature gradually to 28-29°C, treat with ich medication following label directions, and perform daily water changes; maintain treatment for 10-14 days

Velvet Disease

Symptoms

Fine golden or rust-colored dust on body, clamped fins, lethargy, rapid gill movement

Treatment

Increase aeration, raise temperature to 28°C, and treat with copper-based medication or salt; perform daily 25% water changes and remove carbon from filter

Dropsy

Symptoms

Swollen belly, scales standing out like a pinecone, lethargy, loss of appetite

Treatment

Isolate affected fish, improve water quality with frequent changes, treat with antibacterial medication, and provide high-quality food; prognosis is often poor