FaunaHub

Guppy (Poecilia reticulata)

FishFreshwaterAquarium

A male guppy (Poecilia reticulata) with a colourful patterned tail.

Male guppy (Poecilia reticulata), cobra-green morph.

Image: 5snake5, CC0, via Wikimedia Commons.

Overview

The guppy (Poecilia reticulata) is a small, colourful freshwater fish native to northeastern South America and widely kept in home aquariums. Guppies are "livebearers", giving birth to free-swimming young rather than laying eggs, and they are known for the bright, varied colours and patterns of males. They are hardy and popular, but they are still living animals with real care needs.

Habitat & Range

Wild guppies live in warm fresh and brackish waters of South America and nearby islands, including streams, ponds, and ditches. They have also been widely introduced around the world, sometimes deliberately, which can affect native species. In captivity they are kept in heated, filtered aquariums. Aquarium guppies should never be released into local waterways.

Diet

Guppies are omnivores that feed on small invertebrates, algae, and organic matter in the wild, and on prepared foods in aquariums. This page does not give feeding quantities; appropriate diet and amounts depend on the individual fish and tank, and should follow qualified aquarium guidance.

Behavior

Guppies are active, generally peaceful, social fish often kept in groups. Males court females with displays of their colourful fins. They breed readily and frequently in aquariums, so populations can grow quickly, which is something to plan for. As with all fish, behaviour and health depend strongly on water quality and a well-maintained environment.

Human Interaction & Conservation

Guppies have been selectively bred into a huge range of colours and tail shapes and are among the most common beginner aquarium fish. They are aquarium animals, not wildlife; introduced populations can harm native ecosystems, so they should not be released. Responsible keeping means a maintained, filtered tank, attention to water quality, and qualified help if a fish appears unwell. This profile is educational and not a substitute for aquarium-care or veterinary advice.

Appearance & Recognition

Guppies show striking differences between the sexes. Males are small and slender with bright colours and often large, patterned tails, while females are larger, fuller-bodied, and more plainly coloured. Selective breeding has produced many fancy strains with different colours and fin shapes. Their small size and upturned mouth suit feeding near the surface.

Similar Animals

Guppies belong to the livebearer family Poeciliidae, alongside mollies, platies, and swordtails. Among FaunaHub's aquarium profiles, the betta is another popular small freshwater fish, though it is a carnivorous labyrinth fish with very different temperament and care.

Guppy care basics →Aquarium care hub →

More photos of the guppy

A brightly coloured male guppy in an aquarium.

A male guppy showing bred colour variation.

Image: Marrabbio2, CC BY-SA 3.0, via Wikimedia Commons.

Frequently Asked Questions — Guppy

Why do my guppies keep having babies?
Guppies are livebearers that breed readily in aquariums, and females can produce broods regularly. This means populations can grow quickly. Planning for this — through tank size, housing, or guidance from a knowledgeable aquarium source — is part of responsible keeping.
Are guppies good beginner fish?
Guppies are popular with beginners because they are small and adaptable, but "beginner-friendly" does not mean effortless. They still need a properly cycled, filtered, heated tank and good water quality. Treat them as real animals with real needs, not decorations.
Why are male and female guppies so different?
Guppies show strong sexual dimorphism. Males are smaller and brightly coloured with ornate tails used in courtship, while females are larger and more plainly coloured. Selective breeding has further exaggerated male colour and fin variety.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.