Black Swordtail

Introduction: The Black Swordtail is a captivating freshwater fish prized for its stunning black coloration and the signature “sword” on the males’ tail fins. A member of the livebearer family, these active swimmers are a popular choice for both beginners and experienced aquarists.

Scientific Name: Xiphophorus hellerii (Black Swordtail is a color variation)

Water Quality: They thrive in clean, well-maintained tanks with moderate water flow. Regularly scheduled partial water changes are essential.

Water Parameters:

pH Level: 7.0 – 8.3 (slightly alkaline)

GH Level: 8 – 20 dGH

KH Level: 4 – 10 dKH

Feeding: Black Swordtails are omnivores. They enjoy a varied diet of high-quality flake food, brine shrimp, bloodworms, and algae wafers. Supplement their diet with blanched vegetables like zucchini or cucumber.

Tank Mates: Peaceful community fish are ideal tank mates. Good options include tetras, rasboras, corydoras catfish, and other peaceful livebearers. Avoid housing them with fin nippers or aggressive fish.

Substrates and Tank Decorations: Opt for a fine gravel substrate with plenty of hiding places for fry. Live plants provide excellent hiding spots for fry, improve water quality, and add visual interest.

Suitable Plants: Swordtails are not known to be heavy plant eaters. Choose a variety of hardy plants like Amazon Swordtails, Java Ferns, Hornwort, or Water Sprite.

Sexing and Breeding: Males are easily identified by their elongated lower tail fin resembling a sword and a modified anal fin called a gonopodium. Females lack the sword and are generally larger. Black Swordtails are prolific breeders. Females can store sperm for several months, resulting in multiple broods from a single mating. To protect fry, provide dense vegetation or separate breeding tanks.

Maximum Size and Longevity: Males can reach up to 4 inches, while females grow slightly larger. With proper care, Black Swordtails can live for 3-5 years.

Behavior: Black Swordtails are peaceful and social fish. Males can be aggressive towards each other, so maintaining a ratio of more females than males (2-3 females per male) is recommended.

General Information: Black Swordtails are a relatively inexpensive fish, making them a budget-friendly option for hobbyists.

Fun Fact: The “sword” on the male Black Swordtail is not just for show! It’s thought to play a role in attracting females and establishing dominance among males.