Swordtail Guppy

Looks how to spot one

scales and fins

Swordtail Guppies have a slim, torpedo-shaped body typical of guppies. Their most striking feature is the elongated lower tail fin that extends like a sword, giving them a dramatic and elegant appearance. This trait is the result of careful selective breeding and is not found in wild guppies.1

Personality what they are like

Swordtail Guppies are peaceful, social and active swimmers. They do best in groups and are generally non-aggressive, though males may sometimes chase females during breeding. They are excellent community fish when kept with similar-sized, gentle tankmates.15

Daily activity how busy a day looks

They are active swimmers and need space to move. A minimum 10-gallon tank is recommended for a small group, with 20 gallons or more ideal for a community setup. Provide gentle filtration and good oxygenation.1

Grooming and care the hands-on bits

Grooming is not applicable, but regular tank maintenance is essential. Perform weekly water changes of about 30% in a mature aquarium. Use a gentle sponge filter or hang-on-back filter. Keep water parameters stable: temperature 72-82°F (22-28°C), pH 6.8-7.8, hardness 8-12 dGH, and zero ammonia/nitrite.16

Home where they are happiest

Provide a well-planted aquarium with sand or fine gravel substrate. Include live plants such as java moss, anubias, hornwort, and guppy grass. Offer hiding spots with caves, driftwood, or ornaments. They prefer hard water and can tolerate some salinity. Not territorial, but they live in groups and appreciate a peaceful environment.153

Food basics what goes in the bowl

Swordtail Guppies are omnivores. Feed a varied diet including high-quality flake food, micro pellets, frozen foods (bloodworms, brine shrimp, daphnia), live foods (mosquito larvae, baby brine shrimp), and vegetables (blanched spinach, zucchini, spirulina flakes). Feed small amounts 2-3 times daily and remove uneaten food.16

Company who they like around

They are shoaling fish and should be kept in groups of 5 or more. They are peaceful and can be housed with other gentle fish of similar size, such as Corydoras, small rasboras, danios, and other livebearers. Avoid fast, fin-nipping fish like tiger barbs or large cichlids that may see them as prey.562

The story where it all began

The Swordtail Guppy is not a natural species but a selectively bred variety of the common guppy (Poecilia reticulata). Breeders developed the distinctive sword-like extension of the lower tail fin through generations of careful line breeding, selecting individuals with naturally elongated lower caudal fins. The swordtail trait is recessive, so maintaining it requires dedicated breeding efforts. This variety combines the hardiness and ease of care of guppies with the dramatic appearance of swordtail fish, though it is not a hybrid. It is considered somewhat rare and may be more expensive than standard guppy strains.1

Recognised by the official bits

Internationales Kuratorium Guppy Hochzucht (IKGH)

The IKGH recognises 13 guppy standards classified into three groups: long tail, sword tail and short tail. Swordtail Guppies belong to the sword tail group.6