Kohaku Swordtail

Kohaku Swordtail

The Kohaku Swordtail brings the classic Japanese koi look to the freshwater aquarium, with bold red-orange patches on a bright white body. Mature males develop the characteristic elongated lower tail, or “sword.”

Hardy, active, and relatively easy to care for, Kohaku Swordtails are an excellent choice for both beginner and experienced fish keepers, and a standout centerpiece in community aquariums and planted tanks.

Scientific Name: Xiphophorus hellerii (aquarium-bred color strain)
Care Level: Easy
Temperament: Peaceful to Semi-Peaceful
Adult Size: Approximately 3.5–5 inches (females are larger; male length includes the sword)
Minimum Tank Size: 20 gallons (larger for a group)
Temperature: 72–80°F
pH: 7.0–8.0 (prefers moderately hard, alkaline water)
Diet: Omnivore
Water Level: Middle to Top
Breeding: Livebearer / Easy to breed

Swordtails are active swimmers and appreciate an aquarium with plenty of open swimming space along with plants or other areas for cover. Males may spar with each other, so when keeping males and females together, a ratio of approximately 1 male to 2–3 females is recommended to help reduce stress on the females. A secure lid is a good idea, since swordtails can jump.

For healthy growth and vibrant coloration, provide a varied diet of quality flakes or pellets supplemented with foods such as brine shrimp, daphnia, and vegetable-based or spirulina foods.

Please note: The size, shape, and placement of the red patches naturally vary between individual fish, so every Kohaku Swordtail has its own pattern. Males typically develop the sword as they mature. The fish you receive may look a little different from others of the same variety.

Shipping & Live Arrival

• Ships Mon–Wed by UPS Next Day Air in an insulated box with heat or cold packs as needed.
• Mon–Wed orders placed before 12:00 PM PT ship the same day. Thu–Sun orders (and Wed orders after the cutoff) ship the following Monday.
• Live Arrival Guarantee: send a photo of the unopened bag within 2 hours of delivery for store credit or a replacement. Valid on overnight shipping only. Choosing 2-day or any non-overnight shipping voids the guarantee.
• Ships to the lower 48 US states only, no P.O. boxes. Please be home to receive your fish.
• See our Shipping Policy and Live Arrival Guarantee for full details.