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No federal permit to keep

Copella carsevennensis

Copella carsevennensis

Fishes › Tetras, piranhas and pacus (Characiformes) › Lebiasinidae (Pencilfish and splash tetras)

Care follows the pencilfish and splash tetras guide below.

Aquarium hobby
Experience: Intermediate
Copella carsevennensis
Photo: Natural History Museum, CC BY 4.0, via Wikimedia Commons
FamilyPencilfish and splash tetras
Adult lengthup to 2.2 in
WaterFreshwater
HabitatLives in freshwater

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 2.2 in / 5.7 cm).
  • Water: Freshwater.
  • Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
  • Diet: FishBase classes it as a carnivore.
  • 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 30 × 12 in (roughly 18 US gallons); space needed is rated “modest tank”.
  • Water: soft, acidic water, 68–82 °F, pH 4–7, 1–10 dGH.
  • Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more; suited to a community tank.
  • Difficulty: Moderate (Seriously Fish rating).

Short excerpts from the species profile:

  • Setup: “Best kept in a densely-planted aquarium or paludarium with some overhanging vegetation, roots or branches important if you wish to raise fry alongside the adults (see 'Reproduction').”
  • Diet: “Probably a micropredator feeding on tiny invertebrates and other zooplankton in nature.”
  • Tankmates: “Peaceful but somewhat unsuitable for the general community aquarium.”
  • Breeding: “This species deposits its eggs among vegetation, these being guarded by the male during incubation.”

From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167

Group care guide

Pencilfish and splash tetras

Applies to most species in this group. Habitat: Common pencilfish and splash tetras inhabit vegetated South American streams and tributaries, with Copella also entering flooded forest. Individual species can differ, so compare with the species numbers above and the linked sources.

The temperature range is for N. beckfordi; C. arnoldi is documented at 68–82.4°F. N. beckfordi is more adaptable than many congeners. Only C. arnoldi has the documented above-water egg-laying and male splashing behavior. Do not apply the small-pencilfish footprint to Copeina guttata or C. osgoodi; these sources give no adult housing protocol for them. Verify requirements for the other listed Nannostomus individually.

Housing & setup

  • N. beckfordi needs a base of at least 18 × 12 inches; C. arnoldi needs at least 36 × 12 inches for long-term care.
  • Use dense planting, floating plants, branches and leaf litter for shade and broken sight lines.
  • Use gentle filtration for pencilfish; provide well-oxygenated water with slight surface agitation for splash tetras.
  • For breeding C. arnoldi provide about 4 inches between water and cover, plus overhanging spawning surfaces.
  • Use a biologically mature aquarium; splash tetras are sensitive to chemistry swings.

Sources 981982983984

Climate & lighting

Water69.8–80.6°F

Sources 981982983984

Diet

  • Dry foods small enough for their mouths.
  • Daily small live or frozen Artemia nauplii, Moina or grindal worms.
  • Small gut-loaded fruit flies or crickets for C. arnoldi.

Sources 981982983984

Social life

  • Keep N. beckfordi in groups of 10 or more and C. arnoldi in mixed-sex groups of 8–10; choose peaceful small companions. Male pencilfish spar, so provide visual barriers.

Sources 981982983984

Health watch

  • Water-quality stress in immature aquaria.
  • Nutritional deficiencies from unsuitable food sizes or limited diets.
  • Freshwater white spot and other skin/gill parasites.

Sources 981982983984

Understanding the animal

This species is part of a group that hobbyists, aviculturists or zoos keep widely (Pencilfish and splash tetras), so it's included for completeness. It may be rare in captivity itself, or not kept at all. Use the group guide as a starting point and look for species-specific advice from experienced keepers.
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 livesLives in freshwater, in rivers and streams. Uses both the bottom and open water. Lives in groups at the surface of small creeks with clear waters. Also found in ponds where it is found together with Rivulus.
Water it lives inFreshwater.
ClimateTropical climate.
  1. FishBase species summary: Copella carsevennensis
Native climate (measured)

Native climate (measured)

Warm-season highsabout 89°F (up to 90°F in the hottest sampled areas)
Cool-season lowsabout 70°F (down to 68°F in the coldest sampled areas)
Average temperature78–80°F across sampled records
Relative humidity82–84% on average (driest month about 78%)
Rainfallabout 2692 mm a year

Measured at 46 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 livesHome 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
ReproductionDeposits eggs on underside of objects above the water surface. Male in water splashes the clutch periodically. In the aquarium, male and female swim vertically to the surface, flick their tails and leap up to a leaf. — FishBase
BiologyOccurs in groups at the surface of small creeks with clear waters. Also found in ponds where it is found together with Rivulus. Feeds on Ephemeroptera larvae and ants; also on worms, insects and crustaceans. — 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

Average of sources1.9in
FishBase 1642.2
Seriously Fish species profiles 1671.6

Maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.

Water temperature

Reported68–82°F
Seriously Fish species profiles 16768–82

Range the species tolerates; aim for the middle.

pH

Reported4–7
Seriously Fish species profiles 1674–7

Water hardness

Reported1–10dGH
Seriously Fish species profiles 1671–10

Minimum tank footprint

Reported30in
Seriously Fish species profiles 16730

Seriously Fish recommends a tank base of at least 30 × 12 in (about 18 US gallons).

Sources for this sheet

  1. 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.
  2. 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.
  3. Nannostomus beckfordi — Seriously Fish Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  4. Copella arnoldi — Seriously Fish Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
  5. Disorders and Diseases of Fish — Merck Veterinary Manual Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
  6. Parasitic Diseases of Fish — Merck Veterinary Manual Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.