Guppy

Poecilia reticulata

Livebearers

One of the most iconic and widely kept aquarium fish. Renowned for their incredible colors, hardiness, and prolific breeding. As livebearers, they give birth to fully formed, free-swimming fry. Males constantly pursue females for mating; therefore, a ratio of at least 2 females per male is strongly recommended to disperse stress.

At a Glance

Adult Size5 cm
Body ShapeFusiform
Growth RateFast
TemperamentPeaceful
Water TypeBrackish Tolerant
Flow PreferenceLow
Waste OutputHigh
StockingGroup of 3+

Tank Requirements

Minimum Volume38 L
Minimum Length45 cm
FlowLow
Water TypeBrackish Tolerant
Must-Haves in the Tank
Plants - Densely coveredPlants - Floating

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Water Parameters

Temperature2228°C
pH78.5
Hardness830 dGH

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Keep water parameters stable with the right testing and heating gear.

Temperament & Compatibility

Aggression LevelPeaceful
1/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least3 fish
Max per TankNo limit
Can Live Alone?No — needs a group
Behavior Traits
Hyperactive / Fast SwimmerFry Predator

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Male (Fancy)

Males are significantly smaller but boast spectacular colors and large, flowing fins. They are extremely active and will relentlessly court females. Can be kept in a 'bachelor' (male-only) tank to prevent breeding.

Differs in 2 traits from base species

Also known as: Male Guppy, Cobra, Delta Tail, Mosaic

Adult Size3.5 cm
Behavior Traits
Hyperactive / Fast SwimmerFry PredatorLong Finned (Nipper Target)

Female

Females are larger, thicker, and generally less colorful than males (though modern strains have colorful tails). They possess a distinct dark 'gravid spot' near the anal fin and can store sperm for months, dropping fry every 21-30 days.

Differs in 1 trait from base species

Also known as: Female Guppy, Breeder

Adult Size6 cm

Guppy Care Guide Summary

The Guppy, scientifically known as Poecilia reticulata, belongs to the Livebearers family group. Adults reach a maximum size of approximately 5 cm and have a fusiform body shape with a fast growth rate. Classified as peaceful, this species primarily occupies the surface and mid-level zones of the aquarium and produces a high level of biological waste.

To thrive, the Guppy requires a brackish tolerant aquarium with a minimum volume of 38 litres and a tank length of at least 45 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 78.5 and a general hardness of 830 dGH. A low water flow is preferred. An aquarium test kit can help you monitor these values.

The Guppy is a rewarding species to keep, provided its core environmental needs are met. This species is available in 2 varieties: Male (Fancy) and Female. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.

Guppy Habitat Setup

When setting up an aquarium for the Guppy, a low water flow best suits their natural preferences. Because this species occupies the surface and mid-level zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include dense planting to provide cover, break sightlines, and reduce stress and floating plants to diffuse overhead light and create shaded areas.

Guppy Compatibility Notes

Classified as peaceful, the Guppy is a social species that requires the company of its own kind to thrive. When choosing tankmates, their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the surface and mid-level zones can help reduce competition and territorial overlap.

Recommended Tank Sizes

Standard aquarium sizes that meet the minimum volume and length requirements for Guppy.

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Frequently Asked Questions About Guppy

How big does Guppy get?

Guppy (Poecilia reticulata) typically reaches a maximum adult size of approximately 5 cm. They have a fusiform body shape and a fast growth rate.

What tank size does Guppy need?

A minimum aquarium volume of 38 litres and a tank length of at least 45 cm are recommended for Guppy. This ensures enough swimming space and helps maintain stable water conditions.

What water parameters does Guppy need?

Guppy thrives in brackish tolerant conditions with a temperature range of 22–28°C, a pH between 7 and 8.5, and a general hardness of 8–30 dGH. A low water flow is preferred.

Is Guppy peaceful or aggressive?

Guppy is classified as peaceful with an aggression score of 1 out of 10. They are generally well-suited to peaceful community tanks.

Can Guppy live alone?

No, Guppy should be kept in groups of at least 3 to reduce stress and encourage natural behaviour.

Does Guppy have any special tank requirements?

Yes. Guppy benefits from plants - densely covered and plants - floating in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.


Similar Species

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Poecilia wingei

Livebearers
2.5 cm Peaceful

A tiny, vibrant, and highly active livebearer closely related to the Guppy. Males display intense, neon colors and patterns, while females are larger and plainly colored. They are prolific breeders and require hard, alkaline water to thrive.

Goldfish (Comet / Common)

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Platy

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Rosy Barb

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Paradise Fish

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Zebra Danio

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One of the most robust and active aquarium fish available. Native to South Asia, they are a model organism in science due to their genetics. They are extremely active top-level swimmers that must be kept in schools to prevent stress and fin-nipping. They prefer cooler, oxygen-rich water with a current.