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No federal permit to keepGuppy
Poecilia reticulata
Fishes › Killifish and livebearers (Cyprinodontiformes) › Poeciliidae (Livebearers)
The guppy (Poecilia reticulata), also known as the millionfish or rainbow fish, is a member of the family Poeciliidae and, akin to most New World members of the family, is classified as a livebearer.
Care at a glance
Species-specific values
Values researched for this exact species. Where they differ from the group guide below, follow these. Air, surface and water temperatures are listed separately, and each source is kept as published rather than averaged.
| Water temperature | 63–82 °F (17–28 °C) Maintenance recommendations from this source; do not replace with a multisource average. | 250 |
| Water pH | 7–8.5 Maintenance recommendations from this source; do not replace with a multisource average. | 250 |
| Water general hardness | 8–30 dGH Maintenance recommendations from this source; do not replace with a multisource average. | 250 |
| Adult standard length | 60 mm Maximum standard length reported by source; excludes caudal fin, not total body length. | 250 |
| Minimum tank base | length: 45 cm; width: 30 cm Minimum aquarium base recommended by this source, not a tank-volume specification. | 250 |
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 1.1 in / 2.75 cm; the largest recorded was 2.0 in).
- Water: Freshwater (tolerates brackish).
- Temperature: 64–82°F (range recorded for this species).
- pH: 7–8.
- Hardness: 9–19 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: FishBase classes it as a carnivore.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 18 × 12 in (roughly 11 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 63–82 °F, pH 7–8.5, 8–30 dGH.
- Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more; suited to a community tank.
- Difficulty: Easy (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Unfussy, though a planted tank with floating vegetation is appreciated.”
- Diet: “Wild fish are primarily insectivorous, but today's tank-bred fish are far-removed from their ancestors and will accept most foods offered.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Livebearers (guppies, mollies, platies and swordtails)
Applies to most species in this group. Habitat: Warm streams, ponds and brackish waters. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Planted tanks with gentle flow; mollies appreciate harder, slightly brackish water.
Diet
- Flake foods with plant matter, plus live or frozen foods.
Social life
- Peaceful community fish; keep more females than males.
Health watch
- They breed constantly; plan for fry or keep single-sex groups.
Understanding the animal
About this animal
About this animal
Male guppies, which are smaller than females, have ornamental caudal and dorsal fins. Wild guppies generally feed on a variety of food sources, including benthic algae and the larvae of aquatic insects.
Quoted from the Wikipedia article “Guppy” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater and brackish water, in rivers and streams. Uses both the bottom and open water. Inhabits warm springs and their effluents, weedy ditches and canals. |
| Water it lives in | Freshwater / brackish water, 64–82 °F (18–28 °C), pH 7–8, hardness 9–19 dH. |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: internal live bearers, maternal parental care. |
What this means for care
- Keep water within its wild range, 64–82 °F.
- It tolerates or needs brackish water; check salinity needs before setup.
- Parents guard eggs or young, so expect territorial behavior when breeding.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 87°F (up to 94°F in the hottest sampled areas) |
| Cool-season lows | about 57°F (down to 42°F in the coldest sampled areas) |
| Average temperature | 62–80°F across sampled records |
| Relative humidity | 71–80% on average (driest month about 69%) |
| Rainfall | about 1353 mm a year |
Measured at 1525 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The guppy (Poecilia reticulata), also known as the millionfish or rainbow fish, is a member of the family Poeciliidae and, akin to most New World members of the family, is classified as a livebearer. Male guppies, which are smaller than females, have ornamental caudal and dorsal fins. Wild guppies generally feed on a variety of food sources, including benthic algae and the larvae of aquatic insects. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Reproduction | Males are about half the size of females with colorful tail and caudal fin; the anal fin is transformed into a gonopodium for internal fertilization. Males are continuously chasing and mating females. Females can store sperms for later fertilization and may produce young every four weeks. — FishBase |
| Appearance and size | Guppies exhibit sexual dimorphism. While wild-type females are grey in body colour, males have splashes, spots, or stripes that can be any of a wide variety of colours. The development and expression of colour patterns in male guppies is influenced by thyroid hormone levels. — Wikipedia (community-edited) |
| Biology | Adults inhabit warm springs and their effluents, weedy ditches and canals. They are found in various habitats, ranging from highly turbid water in ponds, canals and ditches at low elevations to pristine mountain streams at high elevations. They occur in wide variety of habitats with low predation pressure, usually in very small streams and densely vegetated lakes and springs. — FishBase |
| History and naming | Guppies were first described in Venezuela as Poecilia reticulata by Wilhelm Peters in 1859 and as Lebistes poecilioides in Barbados by De Filippi in 1861. It was named Girardinus guppii by Albert Günther in honour of Robert John Lechmere Guppy, who sent specimens of the species from Trinidad to the Natural History Museum in London. It was reclassified as Lebistes reticulatus by Regan in 1913. — Wikipedia (community-edited) |
Data and studies
Researched care notes
Researched care notes
Findings checked against veterinary, zoo, welfare, keeper and peer-reviewed sources. Air, basking-surface and water temperatures are kept separate, and where sources disagree both are shown. “Study” notes report what a paper measured, not a universal rule.
Guppy
- Guppies favor moderately hard or harder water; Seriously Fish lists pH 7.0–8.5 and hardness 8–30 dGH.1
- Seriously Fish publishes a broad water-temperature range of 17–28°C; that range describes husbandry bounds rather than proving equal welfare at both extremes.1
- Provide planted cover and avoid strong currents that make swimming continuously difficult.1
- Avoid fin-nipping tankmates such as tiger barbs, especially with long-finned ornamental guppies.1
- In mixed-sex groups, keep several females per male to reduce concentrated male pursuit; prolific breeding still requires a population plan.1
- A female previously exposed to males can retain sperm and produce further broods after separation; a female-only tank is not necessarily initially birth-free.1
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Maximum recorded lifespan
Longest recorded lifespan reported by each database; typical lifespans are usually shorter.
Adult length
Common length to maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 18 × 12 in (about 11 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Historical distribution and current drivers of guppy occurrence in Brazil Dias MS et al., Journal of fish biology 2020
- megasat: automated inference of microsatellite genotypes from sequence data Zhan L et al., Molecular ecology resources 2017
- Mycobacterium marinum lymphocutaneous infection Bouceiro-Mendes R et al., Dermatology online journal 2019
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. See all 72 on PubMed → 170
Sources for this sheet
- AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) Peer-reviewed researchCurated, referenced longevity and life-history records for thousands of species; maximum lifespans are often from zoo animals.
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
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