Home / Fishes / Killifish and livebearers / Southern platyfish
No federal permit to keepSouthern platyfish
Xiphophorus maculatus
Fishes › Killifish and livebearers (Cyprinodontiformes) › Poeciliidae (Livebearers)
The southern platyfish, common platy, or moonfish (Xiphophorus maculatus) is a species of freshwater fish in family Poeciliidae of order Cyprinodontiformes.
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 0.9 in / 2.35 cm; the largest recorded was 1.6 in).
- Water: Freshwater.
- Temperature: 64–77°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 24 × 12 in (roughly 14 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 68–79 °F, pH 7–8.2, 10–30 dGH.
- Behaviour: temperament peaceful.
- Difficulty: Beginner (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Not critical but this species does appreciate a planted aquarium, and will be seen at its best if kept in this type of setup.”
- Diet: “Unfussy and will accept most foods, whether frozen, live or dried.”
- Tankmates: “Very peaceful and can be kept with most community species.”
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
A live-bearer, it is closely related to the green swordtail (X. hellerii) and can interbreed with it. It is native to an area of North and Central America stretching from Veracruz, Mexico, to northern Belize.
Quoted from the Wikipedia article “Southern platyfish” (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. Uses both the bottom and open water. Adults occur in warm springs, canals and ditches with typically slow-moving water, silt bottoms and weedy banks. |
| Water it lives in | Freshwater, 64–77 °F (18–25 °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, 64–77 °F.
- Parents guard eggs or young, so expect territorial behavior when breeding.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 89°F (up to 96°F in the hottest sampled areas) |
| Cool-season lows | about 60°F (down to 44°F in the coldest sampled areas) |
| Average temperature | 65–79°F across sampled records |
| Relative humidity | 72–79% on average (driest month about 69%) |
| Rainfall | about 1621 mm a year |
Measured at 250 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 southern platyfish, common platy, or moonfish (Xiphophorus maculatus) is a species of freshwater fish in family Poeciliidae of order Cyprinodontiformes. A live-bearer, it is closely related to the green swordtail (X. hellerii) and can interbreed with it. It is native to an area of North and Central America stretching from Veracruz, Mexico, to northern Belize. The southern platyfish grows to a maximum overall length of 6.0 cm. — 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 | After 24 to 30 days gestation, 20 to 80 young are born (Ref 7020). — FishBase |
| Appearance and size | Maximum length 4.0 cm tl male/unsexed. — FishBase |
| Biology | Adults occur in warm springs, canals and ditches with typically slow-moving water, silt bottoms and weedy banks; 44091, 44894 ). Also inhabit creeks and swamps. They feed on worms, crustaceans, insects and plant matter; 44091). — FishBase |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Common length to maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 24 × 12 in (about 14 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Parasites of ornamental fish commercialized in Macapá, Amapá State (Brazil) Hoshino ÉM et al., Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology: Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria 2018
- Sex determination and sex chromosome evolution in the medaka, Oryzias latipes, and the platyfish, Xiphophorus maculatus Volff JN et al., Cytogenetic and genome research 2002
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 13 on PubMed → 170
Sources for this sheet
- 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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