Home / Fishes / Catfish / Redtail catfish
No federal permit to keepRedtail catfish
Phractocephalus hemioliopterus
Fishes › Catfish (Siluriformes) › Pimelodidae (Long-whiskered catfish)
The redtail catfish (Phractocephalus hemioliopterus), is a large species of South American pimelodid (long-whiskered) catfish.
Care at a glance
Species-specific aquarium care
- Tank: At least 96 in long and 48 in front to back for one adult (adults commonly reach about 23.6 in / 60 cm; the largest recorded was 53.1 in).
- Water: Freshwater.
- Temperature: 68–79°F (range recorded for this species).
- pH: 5.5–6.8.
- Hardness: 0–10 dGH.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- 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, 70–79 °F, pH 6–7.5, 2–12 dGH.
- Behaviour: temperament peaceful.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Strictly speaking, decor isn't necessary for a tank containing an adult, provided the lighting is fairly dim.”
- Diet: “Quite an opportunistic feeder in nature, feeding on fish, invertebrates and fallen fruits.”
- Tankmates: “Whilst it won't hesitate to gobble any smaller fish, it's actually quite peaceful and can be kept alongside other similarly-sized species in suitable surroundings.”
- Breeding: “Not thought to have been achieved in the hobby.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Long-whiskered catfish
Applies to most species in this group. Habitat: South American pimelodids occupy river channels and tributaries, with redtails and shovelnoses also using flooded forests. [fg178-pictus, fg178-redtail, fg178-sorubim]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For P. pictus, use at least 120 × 45 × 45 cm (about 243 L), with open swimming space.
- Adult redtails and P. fasciatum require facility-scale housing: approximately 360 × 240 × 120 cm (10,368 L) is explicitly only a minimum in the reference.
- Provide dim lighting and appropriately sized shelters; use fine sand for pictus.
- For giant species, secure heavy furnishings and avoid swallowable gravel; bare bottoms or large smooth pebbles are alternatives.
- Use efficient biological filtration, regular partial water changes and, for giants, equipment protected in an external sump.
Climate & lighting
| Water | 71.6–77°F |
Diet
- Pictus: sinking prepared foods and frozen bloodworms.
- Earthworms, sized for the fish.
- Giant predators: prawns and mussels.
- Giant predators: white-fish portions; vary foods and reduce feeding frequency as adults mature.
Social life
- Pictus are shoaling fish, preferably six or more in adequate space; adult redtails and shovelnoses can be territorial towards other large pimelodids. Companions must be too large to swallow.
Health watch
- Barbel erosion with deteriorating water quality.
- White spot and poor condition in newly imported pictus.
- Obesity and fatty organ damage from overfeeding or inappropriate mammal meat.
Understanding the animal
About this animal
About this animal
It is known in Venezuelan Spanish as cajaro; in Guyana, it is known as a banana catfish, and in Brazil it is known as pirarara, a fusion of words from the indigenous Tupi language: pirá and arara. It is the only extant species of its genus, Phractocephalus.
Quoted from the Wikipedia article “Redtail catfish” (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, in rivers and streams, lakes. Stays near the bottom. Feeds on fish, crabs and fruits. |
| Water it lives in | Freshwater, 68–79 °F (20–26 °C), pH 5.5–6.8, hardness 10 dH. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
What this means for care
- Keep water within its wild range, 68–79 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 91°F (up to 94°F in the hottest sampled areas) |
| Cool-season lows | about 69°F (down to 61°F in the coldest sampled areas) |
| Average temperature | 77–81°F across sampled records |
| Relative humidity | 77–84% on average (driest month about 75%) |
| Rainfall | about 2228 mm a year |
Measured at 165 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 | The redtail catfish (Phractocephalus hemioliopterus), is a large species of South American pimelodid (long-whiskered) catfish. It is known in Venezuelan Spanish as cajaro; in Guyana, it is known as a banana catfish, and in Brazil it is known as pirarara, a fusion of words from the indigenous Tupi language: pirá and arara. It is the only extant species of its genus, Phractocephalus. The redtail catfish is quite common in the aquarium trade, although it is often sold in its juvenile state, only measuring a few centimeters or inches at the time of sale. — 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 | Maximum length 135 cm tl male/unsexed; maximum published weight 44.2 kg. — FishBase |
| Biology | Adults feed on fish, crabs and fruits. The species is introduced but not established in Florida. — FishBase |
| History and naming | Due to the potentially large size of this species, redtail catfish are considered a game fish by anglers. The current IGFA world-record for weight is from 2010 and belongs to Gilberto Fernandes, of Brazil, with a specimen that weighed-in at 56 kg. It is said that the South American tribes living in the forests do not eat the meat of redtail catfish as it is "black" in coloration. — 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.
Typical adult weight
Average adult body mass in each database (FishBase gives the maximum recorded weight).
Adult length
Common length to 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
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: Pimelodus pictus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Phractocephalus hemioliopterus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Pseudoplatystoma fasciatum Experienced keeper or breederAdded 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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