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No federal permit to keepNiger tetra
Arnoldichthys spilopterus
Fishes › Tetras, piranhas and pacus (Characiformes) › Alestidae (African tetras)
Arnoldichthys is monospecific genus of freshwater ray-finned fish in the family Lepidarchidae.
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 3.8 in / 9.6 cm).
- Water: Freshwater.
- Temperature: 73–82°F (range recorded for this species).
- pH: 6–8.
- Hardness: 5–19 dGH.
- Layout: An open-water swimmer: needs long, open swimming space with few obstacles.
- Diet: Eats a varied diet: mix quality prepared foods with frozen and live foods. 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 47 × 12 in (roughly 29 US gallons); space needed is rated “large tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 75–81 °F, pH 6–7.5, 1–15 dGH.
- Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more; suited to a community tank.
- Difficulty: Easy (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Driftwood branches, roots, smooth stones and aquatic plants can all be used, but be sure to leave sufficient open space for this active species.”
- Diet: “Unfussy and will accept most foods offered.”
- Tankmates: “Peaceful but very active and should not be kept with shy species.”
- Breeding: “Conflicting reports exist.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
African tetras
Applies to most species in this group. Habitat: African freshwater habitats range from the Congo drainage occupied by Congo tetras to large rivers and lakes inhabited by giant tigerfish. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Adult Congo tetras need at least 120 × 30 × 30 cm (about 48 × 12 × 12 inches).
- For Congo tetras, combine plants, floating vegetation and driftwood with open swimming space and good circulation.
- Congo-tetra source parameters are pH 6.0–7.5 and hardness 3–18 dGH; maintain consistently high water quality.
- Hydrocynus goliath needs a facility-scale system: the source suggests roughly 15,000 litres rather than a home aquarium.
- For giant tigerfish, prioritize oxygenation, clean water and open swimming space with minimal hard decor.
Climate & lighting
| Water | 73.4–82.4°F |
Diet
- For Congo tetras: suitable dried omnivore foods including algae-based foods.
- For Congo tetras: small live or frozen worms, insects and crustaceans.
- For tigerfish: appropriately sized dead fish such as whitebait.
Social life
- Congo tetras suit mixed-sex shoals with peaceful companions; fin-nippers damage male fins. Adult giant tigerfish should be kept alone and may attack smaller fish without warning.
Handling
- Giant tigerfish require professional separation and maintenance procedures because adults pose a serious bite hazard.
Health watch
- Ammonia toxicity.
- Nutritional deficiencies.
Understanding the animal
About this animal
About this animal
The only species in the genus is Arnoldichthys spilopterus, the Niger tetra.
Quoted from the Wikipedia article “Arnoldichthys” (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. Feeds on worms, insects and crustaceans. In aquaria, female lays up to 1000 eggs, after vigorous driving by the male, which hatch in 30 to 34 hours. |
| Water it lives in | Freshwater, 73–82 °F (23–28 °C), pH 6–8, hardness 5–19 dH. |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: open water/substratum egg scatterers. |
What this means for care
- Keep water within its wild range, 73–82 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 91°F (up to 92°F in the hottest sampled areas) |
| Cool-season lows | about 71°F (down to 70°F in the coldest sampled areas) |
| Average temperature | 79–80°F across sampled records |
| Relative humidity | 82–84% on average (driest month about 78%) |
| Rainfall | about 2515 mm a year |
Measured at 18 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 | Arnoldichthys is monospecific genus of freshwater ray-finned fish in the family Lepidarchidae. The only species in the genus is Arnoldichthys spilopterus, the Niger tetra. — 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 Niger tetra is a tropical freshwater species found only in a limited number of locations in Nigeria. Despite the word "Niger" in its common name, it is not found in Niger. This is not a misnomer, however, since here this word refers to the Niger River, and the Niger tetra is indeed present in that river, in addition to the Ogun River. — Wikipedia (community-edited) |
| Biology | Feeds on worms, insects and crustaceans. In aquaria, female lays up to 1000 eggs, after vigorous driving by the male, which hatch in 30 to 34 hours. Aquarium keeping: in groups of 5 or more individuals; minimum aquarium size 100 cm. — FishBase |
| Conservation | The Niger tetra is currently classified as endangered by the IUCN due to its limited range coupled with losses to the aquarium trade and ongoing habitat degradation. — 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 in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 47 × 12 in (about 29 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.
- Seriously Fish — Phenacogrammus interruptus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish — Hydrocynus goliath Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Merck Veterinary Manual — Disorders and Diseases of Fish 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.
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