Origins and Classification
- Scientific Name: Xiphophorus hellerii (Black Nubian variety)
- Family: Poeciliidae (Livebearers)
- Origin: Originally from Central America, particularly Mexico, Honduras, and Belize, inhabiting rivers and streams with gentle currents. The Black Nubian Swordtail is a selectively bred color variant developed for its rich, velvety black coloration and elegant tail extension.
- Popularity: A favorite among aquarists for its unique dark appearance, graceful swimming style, and easy care requirements — perfect for both beginner and experienced hobbyists.
🎨 Appearance
- Color: Deep jet-black body with subtle iridescent highlights under aquarium lighting.
- Structure:
- Males possess the signature sword-like tail extension, long and tapered.
- Females have a rounded tail and a more robust body.
- Smooth scales and streamlined body give a sleek, refined look.
- Size: Males typically 4–5 inches (10–12 cm); females slightly larger at 5–6 inches (12–15 cm).
- Lifespan: 3–5 years with proper diet and clean water.
🏡 Tank Requirements
- Tank Size: Minimum 20 gallons for a small group; larger tanks preferred for breeding colonies.
- Water Parameters:
- Temperature: 72–82°F (22–28°C)
- pH: 7.0–8.0
- Hardness: 10–20 dGH
- Lighting: Moderate to bright; enhances the black sheen of their body.
- Substrate: Fine gravel or sand.
- Habitat Setup:
- Provide dense vegetation (live or artificial plants) and open swimming areas.
- Use gentle filtration to mimic natural flow.
- Keep a tight lid — Swordtails may occasionally jump
