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No federal permit to keepThree-ray Bristlenose Pleco
Ancistrus triradiatus
Fishes › Catfish (Siluriformes) › Loricariidae (Plecos)
Ancistrus triradiatus is a species of freshwater ray-finned fish belonging to the family Loricariidae, the suckermouth armoured catfishes, and the subfamily Hypostominae, the suckermouth catfishes.
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 3.6 in / 9.2 cm).
- Water: Freshwater.
- Temperature: 75–82°F (range recorded for this species).
- 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
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 75–86 °F, pH 6.6–7.6, 5–15 dGH.
- Behaviour: temperament peaceful.
- Difficulty: Easy (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “A stream-type setup with a gravel or sand substrate and rounded stones and rocks would simulate its natural biotope, but it's equally at home in a planted tank.”
- Diet: “Mainly vegetarian, so the bulk of the diet should be composed of vegetable matter in both fresh (cucumber slices, blanched spinach etc.) and dried ( algae wafers, Spirulina tablets etc.) forms.”
- Tankmates: “Peaceful and due to its small size is suitable for most communities of peaceful species.”
- Breeding: “Easy once the fish reach maturity.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Plecos (suckermouth catfish)
Applies to most species in this group. Habitat: South American rivers. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Driftwood (some species rasp it for fiber), caves and good flow.
- Common plecos reach 18–24 in; many smaller species stay under 6 in.
Diet
- Algae wafers and vegetables for herbivores; meaty foods for carnivorous species.
Health watch
- Starvation if they're expected to live on algae alone.
Understanding the animal
About this animal
About this animal
This catfish is found in northern South America.
Quoted from the Wikipedia article “Ancistrus triradiatus” (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. Stays near the bottom. |
| Water it lives in | Freshwater, 75–82 °F (24–28 °C). |
| Climate | Tropical climate. |
What this means for care
- Keep water within its wild range, 75–82 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 89°F (up to 95°F in the hottest sampled areas) |
| Cool-season lows | about 68°F (down to 66°F in the coldest sampled areas) |
| Average temperature | 76–81°F across sampled records |
| Relative humidity | 77–78% on average (driest month about 66%) |
| Rainfall | about 2676 mm a year |
Measured at 112 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 | Ancistrus triradiatus is a species of freshwater ray-finned fish belonging to the family Loricariidae, the suckermouth armoured catfishes, and the subfamily Hypostominae, the suckermouth catfishes. This catfish is found in northern South America. — 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 | Ancistrus triradiatus reaches a standard length of 9.2 cm. Ancistrus species develop soft, bushy tentacles on the snout when sexually mature, these are better developed in the males than they are in females. — Wikipedia (community-edited) |
| History and naming | Ancistrus triradiatus was first formally described in 1918 by the German-born American ichthyologist Carl H. Eigenmann, with its type locality given as the ravine of Cramalote, Barrigona and Villavicencio, upper Meta River drainage, Colombia. Eschmeyer's Catalog of Fishes classifies the genus Ancistrus in the subfamily Hypostominae, the suckermouth catfishes, within the suckermouth armored catfish family Loricariidae. — Wikipedia (community-edited) |
Data and studies
Researched care notes
Researched care notes
Findings checked against veterinary, zoo, welfare, keeper and peer-reviewed sources. Air, basking-surface and water temperatures are kept separate, and where sources disagree both are shown. “Study” notes report what a paper measured, not a universal rule.
Bristlenose Pleco
Researched for this genus; applies to its species unless a species note says otherwise.
- The common aquarium bristlenose has uncertain ancestry; do not automatically identify every trade specimen as confirmed Ancistrus cirrhosus.1
- For the common trade bristlenose profile, Seriously Fish gives water temperature 21–26°C, pH 5.5–7.5 and hardness 1–15 dGH.1
- Provide well-oxygenated water and plentiful cover rather than treating the fish as a substitute for aquarium maintenance.1
- Bristlenoses can be territorial toward conspecifics and similarly shaped fish; a peaceful community reputation does not guarantee compatibility between males.1
- Offer dedicated sinking foods with vegetable components and other appropriate variety; the source does not present incidental algae alone as a complete ration.1
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 in nature; aim for the middle.
pH
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.
- Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Seriously Fish — Ancistrus sp. “3” / common bristlenose identification 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.
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