Home / Fishes / Tetras, piranhas and pacus / Payara
No federal permit to keepPayara
Hydrolycus scomberoides
Fishes › Tetras, piranhas and pacus (Characiformes) › Cynodontidae (Payara and dogtooth characins)
The payara (Hydrolycus scomberoides) is a species of dogtooth tetra.
Care at a glance
Species-specific aquarium care
- Tank: An adult reaches about 46.1 in (117 cm). That needs a pond or public-aquarium-scale system, far beyond a home aquarium.
- Water: Freshwater.
- Temperature: 75–82°F (range recorded for this species).
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. FishBase classes it as a carnivore.
- Availability: Mostly kept by public aquariums; private keeping is uncommon.
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 83 × 30 in (roughly 312 US gallons); space needed is rated “very large tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 75–82 °F, pH 6–8, 2–15 dGH.
- Behaviour: temperament peaceful; kept alone; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “The aquarium should ideally be designed to resemble a flowing stream or river with a substrate of variably-sized rocks, sand, fine gravel, and some larger water-worn boulders.”
- Diet: “An obligate but generalised piscivore capable of consuming surprisingly large prey.”
- Tankmates: “Best kept alone or with similarly-sized, non-aggressive fishes since it's actually quite peaceful with those too large to be considered food.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Tetras and other characins
Applies to most species in this group. Habitat: Soft, tea-colored rivers and streams. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Planted tanks with subdued light; many prefer soft, slightly acidic water.
- Schools of six or more (more is better); hatchetfish need tight lids.
Diet
- Small community tetras can use appropriately sized prepared and invertebrate foods; this is not a diet for every characin. Adult Hoplias malabaricus is a fish predator and needs a separate feeding guide.
Social life
- Schooling fish.
Health watch
- Stress and ich if water swings or schools are too small.
Understanding the animal
About this animal
About this animal
This predatory fish is found in the Amazon Basin in tropical South America. It was the first of four species to be described in the genus Hydrolycus.
Quoted from the Wikipedia article “Payara” (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, in rivers and streams, lakes. Uses both the bottom and open water. Apparently carnivorous, probably ichthyophagous. Maximum length reported to reach 40 cm TL. |
| Water it lives in | Freshwater, 75–82 °F (24–28 °C). |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
What this means for care
- Keep water within its wild range, 75–82 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 90°F (up to 94°F in the hottest sampled areas) |
| Cool-season lows | about 69°F (down to 63°F in the coldest sampled areas) |
| Average temperature | 77–81°F across sampled records |
| Relative humidity | 77–84% on average (driest month about 76%) |
| Rainfall | about 2228 mm a year |
Measured at 217 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 payara (Hydrolycus scomberoides) is a species of dogtooth tetra. This predatory fish is found in the Amazon Basin in tropical South America. It was the first of four species to be described in the genus Hydrolycus. — 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 |
| Appearance and size | The most noticeable feature of H. scomberoides is the two long fangs protruding from its lower jaw. These are used to impale its prey, mostly smaller fish. It typically reaches a standard length of about 30 cm, but can reach up to 51 cm. — Wikipedia (community-edited) |
| Biology | Apparently carnivorous, probably ichthyophagous. Maximum length reported to reach 40 cm TL. — 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.
Typical adult weight
Average adult body mass in each database (FishBase gives the maximum recorded weight).
Adult length
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.
pH
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 83 × 30 in (about 312 US gallons).
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.
- Seasonal diet shifts of seven fish species in an Atlantic rainforest stream in Southeastern Brazil (2003) Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish — Paracheirodon innesi Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- 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.
