Product Details

Galaxy Koi Guppy – Poecilia reticulata

Overview:

The Galaxy Koi Guppy is a colourful fancy guppy strain combining koi-style red, orange, white or pale body tones with galaxy-style speckling, iridescence or patterned finnage. As a selectively bred form of Poecilia reticulata, it is peaceful, active and well suited to planted community aquariums with stable, mineral-rich water. Guppies are often recommended for beginners, but fancy strains still need clean water, sensible stocking and protection from fin-nipping tank mates.

Key Identification:

Common Name: Galaxy Koi Guppy
Other Names: Koi Galaxy Guppy, Fancy Guppy, Millions Fish, Guppy
Scientific Name: Poecilia reticulata
Fish Type: Livebearer / Guppy
Water Type: Freshwater, with tolerance of slightly brackish conditions

Natural Range & Habitat:

Wild Poecilia reticulata is native to northern South America and nearby islands, including Venezuela, Barbados, Trinidad and Tobago, though the species has been introduced widely around the world. FishBase records guppies from varied habitats including warm springs, weedy ditches, canals, ponds and small vegetated streams.

The Galaxy Koi Guppy is a domesticated aquarium strain, so it should be treated as a captive-bred ornamental form rather than a wild-type fish.

Appearance & Adult Size:

Galaxy Koi Guppies vary between individuals, but the strain usually combines koi-style red, orange, white or pale body colour with speckled, metallic or galaxy-like patterning. Males are usually smaller, slimmer and more colourful, often with larger decorative tails. Females are larger, fuller-bodied and may show more subdued colour, depending on the line.

Adults usually reach around 3–5 cm, with females often larger than males. FishBase lists Poecilia reticulata at up to 5 cm SL for males or unsexed fish and 6 cm SL for females.

Aquarium Suitability:

This is a good fish for peaceful planted community aquariums, beginner tanks and livebearer setups. Guppies enjoy open swimming space, plant cover, floating plants and gentle to moderate filtration. Fancy males with larger tails should not be kept with persistent fin-nippers or aggressive fish.

They are not suitable for very soft acidic aquariums, rough predator communities or tanks with fish that may nip long fins.

Recommended Aquarium Size:

A practical minimum is 45–60 litres for a small group, with 60–90 litres or more preferred for mixed-sex groups or community aquariums. Larger aquariums are much easier to manage if breeding occurs, as guppies can reproduce quickly.

Water Conditions:

Temperature: 22–26°C
pH: 7.0–8.0
Hardness: Moderately hard to hard preferred
Additional Notes: Guppies are hard-water livebearers and do best in mineral-rich, stable water rather than soft acidic conditions. FishBase lists P. reticulata at pH 7–8 and hardness 9–19 dH, while Fishkeeper recommends pH 7–8 and KH 8–20 degrees for aquarium care.

Temperament & Tank Mates:

Aquarium Category: Community Fish

Galaxy Koi Guppies are peaceful, active community fish. Suitable tank mates include platies, small peaceful rainbowfish, Endler-type livebearers if hybridisation is not a concern, Cory-type catfish in suitable water, bristlenose plecs, peaceful small rasboras, calm tetras that tolerate harder water and dwarf shrimp with caution.

Avoid Tiger Barbs, Serpae Tetras, large cichlids, aggressive gouramis, fin-nipping danios in cramped tanks and any fish large enough to eat adult guppies. If keeping mixed sexes, use a ratio of one male to two or more females to reduce female harassment. Male-only groups can work well for display tanks and help prevent unwanted fry.

Feeding:

Galaxy Koi Guppies are easy-feeding omnivores. Offer quality flakes, micro pellets and livebearer granules as the staple diet. Supplement with frozen or live foods such as daphnia, brineshrimp, cyclops, mosquito larvae and finely chopped bloodworm. Include vegetable matter such as spirulina flakes, algae-based foods or blanched greens. FishBase records wild guppies feeding on zooplankton, small insects and detritus.

Behaviour in the Aquarium:

Guppies are active, social livebearers that spend much of their time in the upper and middle levels. Males display constantly to females and rival males, showing off their colour and finnage. Females give birth to free-swimming fry rather than laying eggs, and young may survive in planted tanks if enough cover is available. Guppies mature quickly, with FishBase noting males mature at around two months and females at around three months.

Care Notes:

Keep Galaxy Koi Guppies in stable, mature water with regular water changes. Avoid sudden temperature drops, poor water quality and very soft acidic conditions. Use a secure lid, as guppies can jump. Fancy strains can be more delicate than wild-type guppies, so choose gentle tank mates and avoid fin-nippers. If you do not want uncontrolled breeding, keep males only or have a plan for fry. Do not mix with Endler’s Livebearers or other guppy strains if you want to maintain the Galaxy Koi line, as they can interbreed and produce mixed-pattern offspring.

Recommended For:

Beginner

Availability:

Common to occasional / Captive-bred fancy strain

Image Disclaimer:

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Natural variation in size, colour, pattern, tail shape, fin length and markings can occur between individual fish.