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No federal permit to keepGulper Catfish
Asterophysus batrachus
Fishes › Catfish (Siluriformes) › Auchenipteridae (Driftwood catfish)
Asterophysus batrachus, the gulper catfish or ogre catfish, is a species of catfish in the family Auchenipteridae.
Care at a glance
Species-specific aquarium care
- Tank: At least 42 in long and 21 in front to back for one adult (adults commonly reach about 9.8 in / 25 cm).
- Water: Freshwater.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- 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 59 × 24 in (roughly 143 US gallons); space needed is rated “very large tank”.
- Water: soft, acidic water, 72–82 °F, pH 5–7, 1–8 dGH.
- Behaviour: temperament species tank; kept alone; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Ideally a soft, sandy substrate should be used though it is not essential.”
- Diet: “An obligate predator by nature, but captive specimens readily accept strips of white fish, whole shrimp, earthworms, and similar once they are recognised as food.”
- Tankmates: “Capable of consuming fishes almost twice as large as itself and thus not recommended for the community aquarium.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Driftwood catfish
Applies to most species in this group. Habitat: These American freshwater catfish include nocturnal insect feeders and fish predators; gulpers hunt shallow blackwater tributaries in the Negro and Orinoco systems. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Provide driftwood, roots and crevice refuges; subdued lighting suits nocturnal gulpers.
- For Asterophysus batrachus, use a base at least 150 × 60 cm (about 60 × 24 inches), preferably with soft sand.
- Use canister filtration or a sump for gulper waste, with surface agitation.
- For gulpers, use a mature system and change 30–50% of the water weekly; source parameters are pH 5.0–7.0 and 1–8 dGH.
- Keep surface feeding access clear for Trachelyopterus fisheri rather than relying on bottom-only feeding.
Climate & lighting
| Water | 71.6–82.4°F |
Diet
- For Trachelyopterus: floating insect-based foods offered when light is low.
- For gulpers: strips of white fish.
- For gulpers: whole shrimp and earthworms.
Social life
- Trachelyopterus fisheri may be less shy in substantial groups, but reaches nearly 30 cm. Asterophysus is a predatory species-tank fish capable of swallowing surprisingly large tankmates.
Health watch
- Ammonia toxicity.
- Nutritional deficiencies.
Understanding the animal
About this animal
About this animal
It is native to the Rio Negro and Orinoco basins in Brazil, Colombia and Venezuela, where it is mostly found in slow-moving waters with many submerged structures.
Quoted from the Wikipedia article “Asterophysus” (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. Stays near the bottom. |
| Water it lives in | Freshwater. |
| Climate | Tropical climate. |
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 91°F (up to 95°F in the hottest sampled areas) |
| Cool-season lows | about 70°F (down to 68°F in the coldest sampled areas) |
| Average temperature | 78–82°F across sampled records |
| Relative humidity | 77–84% on average (driest month about 72%) |
| Rainfall | about 2730 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 | Asterophysus batrachus, the gulper catfish or ogre catfish, is a species of catfish in the family Auchenipteridae. It is native to the Rio Negro and Orinoco basins in Brazil, Colombia and Venezuela, where it is mostly found in slow-moving waters with many submerged structures. — 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 |
| Wild diet | The gulper catfish is a strict carnivore and swallows its prey, mostly other fish, whole. This prey can be exceptionally large for its size, sometimes even larger than the gulper catfish itself (although such feeding attempts can be unsuccessful). — Wikipedia (community-edited) |
| Appearance and size | The gulper catfish grows to a standard length of 25 cm and a total length of 28.5 cm. It has a short, thick-set build and is dark-colored with a whitish belly. Its mouth is quite large, and hence the common name of "gulper catfish". — Wikipedia (community-edited) |
| History and naming | The gulper catfish is currently the only recognized species in the genus Asterophysus, but around 2005, a specimen that possibly represents an undescribed species in the genus was collected in Marajó about 1200 km from the traditionally recognized range of the gulper catfish. — 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.
pH
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 59 × 24 in (about 143 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 — Asterophysus batrachus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Tropical Fish Hobbyist — Bottom of the Tank: Driftwood Catfish 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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