AquaNexus verified profile
Upside-down catfish
Synodontis nigriventris
A small, genuinely social Congo-basin Synodontis specialised for inverted swimming; keep a proper group with shaded undersides, oxygenated water and targeted feeding.
Outcome: PASSED Permanent ID: 709
Profile overview
- Scientific Name
- Synodontis nigriventris
- Identity and search names
- Blotched upside-down catfish, Synodontis nigriventris
- Category
- Freshwater fish
- Subgroup
- Other catfish
- Environment
- Freshwater aquarium
- Origin
- Congo Basin of Central Africa
- Care
- Intermediate
- Adult Size
- 8–10 cm
- Lifespan
- 5–15 years
- Tank
- At least 120 L for a social group of five or more
- Temp
- 23–28 °C
- pH
- 6.0–7.8
- Hardness
- Soft to moderately hard
- Salinity
- Freshwater; no routine salt addition
- Lighting
- Normal aquarium lighting
- Placement
- Lower and mid water, often beneath wood or broad surfaces
- Diet
- Omnivore taking insect larvae, small crustaceans, biofilm, algae and balanced sinking or suspended foods
- Filtration
- Use mature biological filtration with effective mechanical solids capture and turnover matched to the species’ natural flow needs. Protect intakes, preserve established media during cleaning and keep ammonia and nitrite at zero.
- Aeration
- Maintain continuous surface agitation and dependable dissolved oxygen across the whole aquarium. Increase oxygen reserve in warm water, strong-current systems, dense groups, medication periods and power interruptions.
- Maintenance
- Observe feeding, respiration, body condition and social behaviour daily; test nitrogen waste and key chemistry on a schedule; clean mechanical media before trapped waste decomposes; and perform regular temperature- and chemistry-matched water changes.
- Welfare
- Maintain the stated adult space and social structure, verify feeding, and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Persistent upright swimming is not automatically illness, but this species normally spends substantial time inverted. A lone hidden fish is often being kept below its social requirement.
- Biosecurity
- Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.
- Review Status
- PASSED
- Source Status
- CURRENT — accepted identity or explicitly bounded species profile; husbandry, welfare, sources and Australian/South Australian biosecurity rechecked. CURRENT
App-ready care, welfare and biosecurity details
Identity Scope
Single-species profile for Synodontis nigriventris. Preserve permanent AquaNexus ID 709, slug upside-down-catfish and route /species/upside-down-catfish/; retain former combinations, locality labels and trade names only as searchable aliases.
Adult Size And Space
Expected adult size: 8–10 cm. Minimum permanent housing: At least 120 L for a social group of five or more. Plan around adult dimensions, activity, social structure, aggression, oxygen demand and waste production rather than sale size.
Social Structure
Keep at least five or six; provide several broad undersides and caves so the group can rest together without one fish monopolising cover
Swimming Zone
Primary zone: Lower and mid water, often beneath wood or broad surfaces. Keep that zone usable for movement, feeding, refuge and escape.
Feeding Ecology
Omnivore taking insect larvae, small crustaceans, biofilm, algae and balanced sinking or suspended foods
Feeding Plan
Feed small varied portions once or twice daily, including after lights dim; place food where inverted swimmers can reach it without bottom-fish competition
Water Stability
Maintain 23–28 °C; pH 6.0–7.8; hardness or minerals: Soft to moderately hard; salinity: Freshwater; no routine salt addition. Stable oxygenation and nitrogen-cycle control matter more than chasing one exact value.
Habitat Structure
Dim, well-oxygenated Congo-style aquarium with wood, broad leaves, overhangs, caves and open midwater routes; inverted swimming and resting are normal for this species
Compatibility Plan
Suitable with peaceful fish too large to swallow that do not harass nocturnal catfish; avoid keeping one alone or crowding every underside
Breeding Plan
Cave spawning has been reported, but repeatable species-specific aquarium protocols are limited Parental care: Do not assume routine parental care; remove or protect eggs only after a confirmed spawning observation.
Quarantine
Quarantine new livestock in a separate cycled system for at least 30 days. Observe appetite, respiration, waste, skin, fins and behaviour; use dedicated equipment and never add transport water to the established aquarium.
Welfare Checks
Maintain the stated adult space and social structure, verify feeding, and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Persistent upright swimming is not automatically illness, but this species normally spends substantial time inverted. A lone hidden fish is often being kept below its social requirement.
Biosecurity And Release
Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.
Main Risk
Persistent upright swimming is not automatically illness, but this species normally spends substantial time inverted. A lone hidden fish is often being kept below its social requirement.
Adult Projected Load
Plan filtration and stocking for the full adult size (8–10 cm), the complete social group and peak feeding waste, not the current shop size. Permanent housing remains At least 120 L for a social group of five or more.
Filtration
Use mature biological filtration with effective mechanical solids capture and turnover matched to the species’ natural flow needs. Protect intakes, preserve established media during cleaning and keep ammonia and nitrite at zero.
Aeration
Maintain continuous surface agitation and dependable dissolved oxygen across the whole aquarium. Increase oxygen reserve in warm water, strong-current systems, dense groups, medication periods and power interruptions.
Maintenance
Observe feeding, respiration, body condition and social behaviour daily; test nitrogen waste and key chemistry on a schedule; clean mechanical media before trapped waste decomposes; and perform regular temperature- and chemistry-matched water changes.
Overridable Warnings
Warnings are decision support, not permission to ignore welfare limits. Override only with specimen-specific evidence, equivalent risk controls and a recorded reason; never override legal, biosecurity, provenance or no-release requirements.
Sources and review basis
- Eschmeyer’s Catalog of Fishes — Synodontis nigriventris: Taxonomy — accepted name, former combinations, synonyms and identity cross-check
- Binning and colleagues — swimming mechanics of Synodontis nigriventris: Behaviour and ecology — specialised inverted swimming and posture
- IUCN Red List search — Synodontis nigriventris: Conservation and provenance — wild status, locality and collection-risk cross-check
- PIRSA — South Australian noxious fish list: Australian biosecurity — current South Australian possession, trade and movement restrictions
- DAFF — importing live ornamental fish to Australia: Australian biosecurity — national live-fish import pathways and permitted-species warning
AquaNexus uses original editorial synthesis. Exact import, possession, movement and disposal requirements must be rechecked with the current authority before acquisition or transfer.