Care at a glance
Species-specific aquarium care
- Tank: At least 30 in long and 15 in front to back for one adult (adults commonly reach about 7.0 in / 17.7 cm).
- Water: Freshwater.
- Temperature: 64–79°F (range recorded for this species).
- pH: 5.8–8.
- Hardness: 0–30 dGH.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- Diet: 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, 64–79 °F, pH 5.8–8, 3–30 dGH.
- Behaviour: temperament peaceful.
- Difficulty: Easy (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “The decor used is not critical but the fish must be provided with some hiding places.”
- Tankmates: “A peaceful and gregarious species but it will probably eat small fish when adult.”
- Breeding: “Not thought to have been achieved in aquaria.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Asian and African whiskered catfish
Applies to most species in this group. Habitat: Bagrids span sheltered Southeast Asian streams and muddy rivers as well as African lake habitats, including Lake Malawi for Bagrus meridionalis. [fg247-siamensis, fg247-nemurus, fg247-kampoyo]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For one Pseudomystus siamensis, provide at least 120 × 30 × 30 cm (48 × 12 × 12 inches), with much more bottom area for multiple fish.
- Use dim lighting and abundant pipes, pots or tangled wood as daytime refuges for nocturnal Pseudomystus.
- Break sightlines into separate bottom territories.
- Position or protect heaters so resting scaleless catfish cannot burn themselves.
- Plan accommodation around adult size: Hemibagrus nemurus reaches 65 cm standard length and B. meridionalis is reported to 150 cm; the small-species tank minimum is unsuitable for them.
Diet
- Prawns and other crustacean flesh.
- Mussels or cockles.
- Earthworms.
- Accepted complete sinking foods; initially feed Pseudomystus after lights-out.
Social life
- P. siamensis eats swallowable companions and defends bottom territories; combine only with appropriately sized fish and sufficient separate refuges. Do not extrapolate its compatibility to every bagrid.
Health watch
- Contact burns from accessible heaters.
- Fat deposition and organ degeneration from inappropriate mammal or poultry meat.
- Ammonia toxicity.
- Infections introduced with livestock or live feeder fish.
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, lakes. Stays near the bottom. Found in lakes, tanks, rivers, canals and beels. Oviparous, distinct pairing possibly like other members of the same family. |
| Water it lives in | Freshwater, 64–79 °F (18–26 °C), pH 5.8–8, hardness 30 dH. |
| Climate | Tropical climate. |
What this means for care
- Keep water within its wild range, 64–79 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 98°F (up to 107°F in the hottest sampled areas) |
| Cool-season lows | about 54°F (down to 48°F in the coldest sampled areas) |
| Average temperature | 75–82°F across sampled records |
| Relative humidity | 60–76% on average (driest month about 54%) |
| Rainfall | about 1476 mm a year, with strong wet and dry seasons |
Measured at 79 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 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 |
| Biology | Facultative air-breathing in the genus; Found in lakes, tanks, rivers, canals and beels. Oviparous, distinct pairing possibly like other members of the same family. Caught with other fishes from fishing operations. — 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.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 47 × 12 in (about 29 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Prevalence and Intensity of Cornudiscoides Agarwali (Monogenoidea) on the Gills of Day's Mystus (Mystus Bleekeri) in Relation to Some Ecological and Biological Factors from Arunachal Pradesh, India Tripathi A et al., Helminthologia 2019
- Two novel species of Gyrodactylus (Platyhelminthes: Monogenoidea: Gyrodactylidae) parasitising Day's mystus, Mystus bleekeri (Siluriformes: Bagridae), with an annotated checklist of gyrodactylids reported from the fishes of India Singh S et al., Journal of helminthology 2026
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. 170
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: Pseudomystus siamensis Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- FishBase: Hemibagrus nemurus Peer-reviewed researchAdded in the 2026 source-checked care-guide review.
- FishBase: Bagrus meridionalis Peer-reviewed researchAdded 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.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
