Home / Fishes / Tetras, piranhas and pacus / Gery's Piranha
No federal permit to keepGery's Piranha
Serrasalmus geryi
Fishes › Tetras, piranhas and pacus (Characiformes) › Serrasalmidae (Piranhas and pacus)
Serrasalmus geryi, known as the violet line piranha or Gery's piranha, is a species of freshwater ray-finned fish belonging to the family Serrasalmidae, which includes the pacus, piranhas and related fishes.
Care at a glance
Species-specific aquarium care
- Tank: At least 36 in long and 15 in front to back for one adult (adults commonly reach about 7.1 in / 18.1 cm).
- Water: Freshwater.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- 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 × 24 in (roughly 114 US gallons); space needed is rated “large tank”.
- Water: 72–84 °F, 5–12 dGH.
- Behaviour: temperament species tank.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Serrasalmus geryi lives in open rivers and thus a well-oxygenated set-up with a sandy substrate and some good-sized driftwood roots and branches should simulate its habitat quite closely.”
- Diet: “Wild fish are known to consume the fins and scales of other species, and probably prey on smaller fish and insects too.”
- Tankmates: “Should only be considered as a specimen fish for the enthusiast.”
- Breeding: “There are rumours that the species has been successfully bred in aquaria, but scant details are available.”
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
About this animal
About this animal
It is found in the lower Tocantins and Araguaia Rivers of Brazil. The species is notable for being one of only the members of the genus Serrasalmus that can coexist with others of the same species in captivity; however, caution is advised.
Quoted from the Wikipedia article “Serrasalmus geryi” (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. |
| Water it lives in | Freshwater. |
| Climate | Tropical climate. |
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 88°F (up to 94°F in the hottest sampled areas) |
| Cool-season lows | about 55°F (down to 52°F in the coldest sampled areas) |
| Average temperature | 71–80°F across sampled records |
| Relative humidity | 73–76% on average (driest month about 63%) |
| Rainfall | about 1571 mm a year |
Measured at 17 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 | Serrasalmus geryi, known as the violet line piranha or Gery's piranha, is a species of freshwater ray-finned fish belonging to the family Serrasalmidae, which includes the pacus, piranhas and related fishes. It is found in the lower Tocantins and Araguaia Rivers of Brazil. The species is notable for being one of only the members of the genus Serrasalmus that can coexist with others of the same species in captivity; however, caution is advised. Gery's piranha reaches sizes up to 12 inches in length. — 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 body shape of Serrasalmus geryi is very laterally compressed, similar to other Serrasalmus genus members S. altuvei, S. hastatus, S. compressus and S. altispinis. The fish is distinctive at all ages, possessing a broad dark stripe running from the lower mouth to the top of the beginning of the dorsal fin. S. geryi does not exhibit sexual dimorphism. — Wikipedia (community-edited) |
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
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; aim for the middle.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 47 × 24 in (about 114 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.
- 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.
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