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No federal permit to keepBlotched upsidedown catfish
Synodontis nigriventris
Fishes › Catfish (Siluriformes) › Mochokidae (Synodontis and squeaker catfish)
Synodontis nigriventris, common name the blotched upside-down catfish or back-swimming Congo Catfish is a species of upside-down catfish native to the Congo Basin of Cameroon, the Democratic Republic of the Congo and the Republic of the Congo.
Intro from Wikipedia (CC BY-SA 4.0)
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: 72–79°F (range recorded for this species).
- pH: 6–8.
- Hardness: 5–12 dGH.
- 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.
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
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 75–82 °F, pH 6–7.5, 5–20 dGH.
- Behaviour: a shoaling fish best kept in a group of six or more.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “A dimly lit aquarium with a soft substrate and rocks, pieces of driftwood and twisted roots arranged to form hiding places suits this species.”
- Diet: “Synodontis are omnivorous and are most unfussy in terms of feeding.”
- Tankmates: “One of the most gentle members of the genus, S.”
- Breeding: “Has been achieved in aquaria but details are very scarce.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Synodontis and squeaker catfish
Applies to most species in this group. Habitat: African mochokids include Synodontis from vegetated riverbanks and distinct species from rocky habitats in the East African Rift lakes. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For a small S. nigriventris group, provide at least 75 × 30 × 30 cm (30 × 12 × 12 in), about 70 litres; larger species need more space.
- Use sand or another soft substrate to protect sensitive barbels.
- Provide plentiful daytime shelters: wood and roots for river species, rock caves for Rift-lake species.
- For S. nigriventris, use dim lighting and broad-leaved or floating vegetation with sheltered undersides for inverted resting.
- Separate water-chemistry plans: S. nigriventris is listed at pH 6.0–7.5 and 5–20 dGH; S. petricola at pH 7.5–8.5 and 10–35 dGH.
Climate & lighting
| Water | 75–82°F |
Diet
- Complete dried foods appropriate to adult size.
- Live or frozen aquatic foods as part of an omnivorous diet.
- Shelled peas or cucumber; S. nigriventris may also feed inverted at the surface.
Social life
- Keep S. nigriventris in groups of at least three or four and S. petricola in groups of four or more. Larger Synodontis can be territorial toward other catfish and eat small tankmates; provide separate shelters and ample space.
Health watch
- Barbel damage associated with abrasive substrate.
- Ammonia-related illness in poorly maintained systems.
- Nutritional deficiencies from an unbalanced diet.
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. Uses both the bottom and open water. Feeds mainly at night on insects, crustaceans and plant matter. |
| Water it lives in | Freshwater, 72–79 °F (22–26 °C), pH 6–8, hardness 5–12 dH. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: clutch tenders. |
What this means for care
- Keep water within its wild range, 72–79 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 88°F (up to 89°F in the hottest sampled areas) |
| Cool-season lows | about 66°F (down to 64°F in the coldest sampled areas) |
| Average temperature | 76–78°F across sampled records |
| Relative humidity | 78–83% on average (driest month about 76%) |
| Rainfall | about 1686 mm a year |
Measured at 45 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 | Synodontis nigriventris, common name the blotched upside-down catfish or back-swimming Congo Catfish is a species of upside-down catfish native to the Congo Basin of Cameroon, the Democratic Republic of the Congo and the Republic of the Congo. — 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 |
| Behavior | Synodontis nigriventris are mostly nocturnal, and feed on insects, crustaceans, and plant matter. The young fish do not swim upside-down until they are about two months old. Adults swim and rest upside down in the water. — Wikipedia (community-edited) |
| Reproduction | The parents tend their clutch more than they guard it. — FishBase |
| Appearance and size | Blotched upside-down catfish are small, reaching a maximum of 9.6 cm SL. Like other members of the family Mochokidae, they have large eyes, a large dorsal fin and three pair of barbels. These fish are adapted to spend most of their time upside-down. — Wikipedia (community-edited) |
| Biology | Feeds mainly at night on insects, crustaceans and plant matter. Aquarium keeping: in groups of 5 or more individuals; minimum aquarium size 80 cm. — 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
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.
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 — synodontis nigriventris Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish — synodontis petricola Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Practical Fishkeeping — Frequently asked questions on Synodontis 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.
- 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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