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FishbeginnerFreshwater

Lyretail Swordtail

Xiphophorus hellerii

AnimaliaChordataActinopterygii

Variety of Swordtail · lyretail

📍 Central America

Ask Finn

A fin-shape variety of the swordtail where both the upper and lower lobes of the caudal fin are elongated, creating a symmetrical lyre shape while still retaining a sword extension on the lower lobe in males. It is as hardy as standard swordtails and thrives in community tanks with hard, alkaline water, though fin-nippers should be avoided.

Size4.5"
Min Tank20g
School3+
peaceful
Zonemid

Care Guide

Diet

Lyretail 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, daphnia, or bloodworms. Include vegetable matter such as blanched spinach or algae-based foods to support their digestive health. Feed small amounts once daily, only what they can consume in 2-3 minutes.

Behavior

These peaceful, active fish are strong swimmers that prefer the mid-water column and spend much of their time exploring and grazing. Males may display territorial behavior toward each other, so multiple males should only be kept in larger tanks with plenty of visual barriers. They are social fish that do best in groups of 3 or more and are generally compatible with community tank inhabitants.

Breeding

Lyretail swordtails are livebearers that breed readily in captivity when kept in groups with a female-to-male ratio favoring females (3:1 or higher). Fry are born fully formed and should be removed to a separate rearing tank with dense vegetation to prevent predation by adults. Breeding is not difficult, but controlling population growth in established tanks can be challenging.

Common Diseases

Fin Rot

Symptoms

Frayed, discolored, or deteriorating fin edges; lethargy; loss of appetite

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 (White Spot Disease)

Symptoms

Small white spots on body and fins, excessive scratching against objects, rapid breathing

Treatment

Raise water temperature gradually to 28-29°C, perform daily water changes, and treat with ich medication or aquarium salt for 7-10 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, perform daily water changes, and treat with copper-free velvet medication for 7-14 days

Dropsy

Symptoms

Swollen abdomen, protruding scales, lethargy, loss of appetite

Treatment

Isolate affected fish, perform frequent water changes, improve water quality, and treat with antibacterial medication; prognosis is often poor

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Water it likes

ph
7.0–8.3
ammonia
0 ppm
nitrate
<20 ppm
temperature
64–79°F (18–26°C)

Stats

Community tips0
Kept by0 hobbyists