Poeciliidae

Cobra Guppy

Poecilia reticulata

A form of:Common Guppy

The Cobra Guppy, scientifically known as Poecilia reticulata (Cobra variety), belongs to the family Poeciliidae. Its distinctive feature is a pattern of vertical stripes running along the posterior part of its body. The coloration of these fish varies widely: green, red, blue, and yellow hues, as well as various combinations thereof, can be found. Particularly notable is the large, flowing caudal fin, adorned with numerous contrasting speckles and irregularly shaped spots. These characteristics primarily apply to males. Females, though larger, appear less vibrant and expressive.

Tank
from 40 L (11 gal)
Temperature
17 – 28 °C (63 – 82 °F)
Size in aquarium
3 – 6 cm (1.2 – 2.4 in)
Acidity
pH 7–8.5
Natural rangeRange on the map
  • Antigua Barbuda
  • Barbados
  • French Guiana
  • Guyana
  • Suriname
  • Trinidad and Tobago
  • Venezuela

Tank conditions

Plan the tank stocking
Temperature
17 – 28 °C (63 – 82 °F)
Water pH
Neutral (7) – Slightly alkaline (8.5)
Water dH
Medium hardness (10) – Very hard (30)
Water salinity
low (3–5 g/L)
Size in aquarium
3 – 6 cm (1.2 – 2.4 in)
Lifespan
3 years
Temperament
Peaceful (regular)
Toward small fish
not a predator
Required aquarium volume
from 40 L (11 gal)
Lighting
dimmed
Substrate
any (no restrictions)
Water flow
weak or moderate
Swimming level
near the surface
Feeding
Any (universal)
Keeping
Mixed solitary / pair / group
Jumping
noticeable a lid is needed
  • Lifespan. A lifespan to expect under good care, not a measured value: it depends heavily on tank volume, water quality and diet — and for selectively bred forms, on their origin as well.
  • Toward small fish. Based on the Predators category in the catalog or the temperament in the species parameters. “A risk to small fish” means the species is not a predator by habit, yet will swallow any fish that fits in its mouth.
  • Required aquarium volume. This is a husbandry recommendation, not a measured value: the volume depends on the keeping mode (mixed (solitary / pair / group)), footprint, decor and tank mates.

Care and keeping

Description

The Cobra Guppy is a selectively bred form of Poecilia reticulata, distinguished by a characteristic pattern on its body resembling snakeskin, created by a combination of vertical stripes and mosaic spots. Males reach 3–4 cm in length and have large, flowing fins with contrasting speckles. Females are larger, growing up to 5–6 cm, but have less vibrant coloration and shorter fins.

Habitat

In the wild, the guppy's ancestors inhabit fresh and brackish waters of South America and the Caribbean islands, such as Venezuela, Guyana, Trinidad, and Tobago. They prefer slow-moving river sections with dense vegetation. The Cobra variety is a result of artificial selection and is not found in natural conditions.

Behavior and Compatibility

Peaceful and active fish, suitable for community tanks with similarly sized tankmates. Intraspecific conflicts are absent; males may show activity towards females but are not aggressive. It is recommended to avoid cohabitation with fin-nipping species, such as some types of barbs.

Care and Maintenance

These fish are rightfully considered among the easiest species to keep, distinguished by their great unpretentiousness and excellent ability to adapt to various conditions. They can live in an aquarium with minimal decor or in a densely planted tank, giving the aquarist freedom in design choices. The Cobra Guppy is undemanding regarding water parameters, thriving in a wide range of pH and GH values, including brackish water. Temperature also does not play a critical role. They can stay for extended periods or permanently in unheated aquariums if these are located in living areas (apartments, houses). However, such adaptability should not be misleading: like other species, the Cobra Guppy is sensitive to the accumulation of organic waste and requires regular care. Essential procedures include weekly partial water changes and timely removal of food remnants, excrement, and other pollutants. Regarding feeding, the guppy's omnivorous nature and the abundance of available foods make it easy to choose an optimal diet. Dry foods in the form of flakes or granules will be a good choice. Regarding behavior and compatibility: intraspecific conflicts are absent. Both females and males, especially, demonstrate a peaceful disposition. Despite some competition between males, it does not escalate into fights. The Cobra Guppy is compatible with most species of similar size and temperament. It is recommended to avoid cohabitation with fish prone to damaging other fish's fins, for example, some types of barbs.

Diet

An omnivorous species, in nature, it feeds on small invertebrates and algae. In the aquarium, they accept all types of food: dry flakes and granules, frozen or live products. To maintain health and vibrant coloration, it is recommended to diversify the diet with plant supplements, such as lettuce or spinach leaves.

Breeding and Reproduction

A livebearing species that does not require complex conditions for breeding. Fertilization occurs inside the female, after which she gives birth to fully formed fry every 3–6 weeks. In a community tank, fry survival is low, so it is recommended to move pregnant females to a separate container with fine-leaved plants.

Diseases

They are sensitive to the accumulation of nitrogenous compounds (nitrites and nitrates) in the water, which can lead to fin rot or a general weakening of the immune system. Prevention includes regular water changes, maintaining substrate cleanliness, and adhering to environmental parameters. In case of poor health, short-term use of table salt at a concentration of up to 1–2 grams per liter is permissible.

How to choose

When purchasing, choose active fish with clean fins showing no signs of damage, film, or spots. It is important to look for the absence of emaciation and sunken bellies. It is recommended to acquire specimens from reputable breeders, as selectively bred forms require stable keeping conditions from birth.

Compatibility

There are no pair reviews for this species yet — check tankmates in the matcher.

All tankmates

Plants and this fish

Matching water does not mean the plant will stay intact.

Frequently asked questions

The essentials: size, tank volume, water parameters and care

How big does Cobra Guppy get?

An adult reaches 3–6 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.

What size aquarium does Cobra Guppy need?

The recommended volume is 40 L. A smaller tank speeds up nitrate build-up and raises stress levels.

What water parameters does Cobra Guppy need?

Temperature 17–28 °C, pH 7–8.5, hardness 10–30 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.

How long does Cobra Guppy live?

Around 3 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.

Is Cobra Guppy aggressive?

Temperament: peaceful (regular). Keep this in mind when choosing tank mates.

How many Cobra Guppy should be kept together?

Recommended setup: mixed (solitary / pair / group). Ignoring this is a common cause of stress and disease.

What does Cobra Guppy eat?

Diet type: any (universal). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.

What is the scientific name of Cobra Guppy?

The scientific name of the species is Poecilia reticulata, family Poeciliidae. It also appears in the literature as: Acanthophacelus guppii, Acanthophacelus reticulatus, Girardinus guppii.

Similar fishes

Matched by family, categories and overlapping keeping conditions

Albino Guppy

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Blue Guppies, known scientifically as Poecilia reticulata (Blue variety), belong to the Poeciliidae family. This name is a generalization and encompasses various breeds where blue is the dominant color. It is mainly…

Common Guppy

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Poecilia reticulata

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The Common Guppy, also known as the Wild Guppy (scientific name Poecilia reticulata), belongs to the family Poeciliidae. It is distinguished from the numerous selective breeding forms developed by humans by its more…

Other scientific names and conservation status

Other scientific names
Acanthophacelus guppii, Acanthophacelus reticulatus, Girardinus guppii, Girardinus reticulatus, Haridichthys reticulatus, Heterandria guppyi
Poecilia reticulata
strain Cobra
Conservation status
Least concernLC