BERLIN SWORDTAIL | XIPHOPHORUS HELLERI

The Berlin Swordtail (Xiphophorus helleri) is a vibrant and lively freshwater fish known for its elegant sword-like tail extension and striking coloration. This variety typically features a bold red or orange body accented by a distinct black stripe running along its side, sometimes extending into the tail — a pattern known as the “Berlin” mark. Males are more vividly colored and have the characteristic elongated lower tail fin, while females are larger and rounder-bodied.

Berlin Swordtails grow to about 4–5 inches and do best in aquariums of 20 gallons or larger. They thrive in warm, clean water with temperatures between 72–82°F, a pH of 7.0–8.2, and moderate hardness. A well-planted tank with open swimming space and gentle filtration provides the perfect environment for them to display their active, social behavior.

These fish are peaceful but energetic and mix well with other community fish such as mollies, platies, Corydoras, tetras, and danios. Males can sometimes spar with each other, so it’s best to keep one male with multiple females to maintain harmony.

Berlin Swordtails are livebearers, meaning they give birth to free-swimming fry rather than laying eggs. If breeding is desired, provide dense plants or breeding grass for fry to hide from adult fish.

They’re omnivores and will thrive on a balanced diet of high-quality flakes, pellets, and frozen or live foods such as brine shrimp, daphnia, and bloodworms. With their vivid coloration, distinctive tail, and hardy nature, Berlin Swordtails make a lively and attractive addition to any community freshwater aquarium.