Home / Fishes / Tetras, piranhas and pacus / Red Ruby Piranha
No federal permit to keepRed Ruby Piranha
Serrasalmus maculatus
Fishes › Tetras, piranhas and pacus (Characiformes) › Serrasalmidae (Piranhas and pacus)
Care follows the piranhas, pacus and silver dollars guide below.
Care at a glance
Species-specific aquarium care
- Tank: At least 60 in long and 21 in front to back for one adult (adults commonly reach about 10.4 in / 26.4 cm).
- Water: Freshwater.
- Layout: An open-water swimmer: needs long, open swimming space with few obstacles.
- 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.
- Safety: Can injure people (sharp spines, teeth or electric shock): use nets and care when working in the tank.
- Availability: Rarely or never seen in the aquarium trade; expect to source it from specialists or not at all.
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 47 × 18 in (roughly 64 US gallons); space needed is rated “large tank”.
- Water: 70–86 °F, 5–15 dGH.
- Behaviour: temperament species tank.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Requires a well-oxygenated set-up, ideally furnished with a sandy substrate and some driftwood roots and branches to provide cover.”
- Diet: “Wild fish are opportunistic, feeding on the fins and flesh of other species as well as smaller fishes, insects and crustaceans.”
- Tankmates: “Should only be considered as a specimen fish for the enthusiast since it doesn't make a good tankmate for anything else.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Piranhas, pacus and silver dollars
Applies to most species in this group. Habitat: South American rivers. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Large tanks with strong filtration; pacus grow to over 2 ft and outgrow almost every home aquarium.
Diet
- Silver dollars: plant-based foods. Piranhas: fish, shrimp and pellets.
Health watch
- Piranhas are banned in many states. Never release pacus.
Understanding the animal
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, mangroves. Occurs usually in small groups of up to 20 individuals which appear to have a definite range within a pond or a creek. Observed to be active mainly during the day. Larger fish extend their foraging until about 9 at night. where it stays in the shallows near the bottom, sheltered among vegetation. |
| Water it lives in | Freshwater. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 89°F (up to 92°F in the hottest sampled areas) |
| Cool-season lows | about 54°F (down to 46°F in the coldest sampled areas) |
| Average temperature | 66–80°F across sampled records |
| Relative humidity | 72–78% on average (driest month about 65%) |
| Rainfall | about 1475 mm a year |
Measured at 377 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.
| 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 | Maximum length 26.4 cm tl male/unsexed; maximum published weight 420.00 g. — FishBase |
| Biology | Occurs usually in small groups of up to 20 individuals which appear to have a definite range within a pond or a creek. Observed to be active mainly during the day. Larger fish extend their foraging until about 9 at night. where it stays in the shallows near the bottom, sheltered among vegetation. — 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; aim for the middle.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 47 × 18 in (about 64 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.
- 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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