Suckermouth Catfish
The suckermouth catfish — known to aquarium keepers worldwide as the pleco — is native to northeastern Brazil, where it lives in tropical rivers and streams as part of the natural bottom community.
It's not a primary target species, but anglers fishing Brazilian rivers do encounter them, and knowing what you've got on the line matters. They're bony and rarely eaten, but catching one on light tackle is a genuine surprise.
Scientific Name: Hypostomus plecostomus
Also known as Pleco, cascudo, acari
- Body covered in hard, bony plates (scutes) along the upper head and flanks — looks almost prehistoric; the belly is soft, unarmored skin.
- Brown to tan base color with darker brown spots across the body and fins; pattern helps it blend into rocky or woody substrate.
- Underslung sucker mouth positioned on the flat underside of the head — the defining ID feature that separates it from other catfish.
- Typical fish run 25–30 cm; larger individuals can reach 50 cm, though fish that size are uncommon in the wild.
What to know
Habitat Distribution
- Native to northeastern Brazil and the coastal river drainages of the Guianas — this is where the species genuinely belongs, not an introduction.
- Lives in tropical freshwater: rivers, streams, and their associated pools, typically over rocky, sandy, or woody bottom where algae and detritus accumulate.
- Tolerates a wide pH range (roughly 6.2–8.2) and prefers water temperatures between 20–28°C, which fits the warm lowland rivers of its native range.
- Stays close to the bottom and gravitates toward structure — submerged logs, rock faces, and root tangles where it can rasp algae and shelter.
Key Locations
- Northeastern Brazil river drainages — the species' native range.
Specific Spots
- Rocky outcroppings and submerged boulders are prime holding water — the fish use them for both feeding and cover.
- Submerged timber and root systems in slower river sections concentrate fish, especially where algae growth is heavy on the wood.
- Shallow, slower-moving margins near current breaks, where detritus settles and algae builds up on hard surfaces.
Suckermouth Catfish FAQ
Answers from onWater's species guide.
What are the best lures and bait for Suckermouth Catfish?
Natural bottom baits, earthworms, dough baits, or cut bait, are the most reliable way to hook these fish incidentally; they're not reliably caught on artificial lures. Small hooks (size 6–10) fished tight to the bottom near rocky or woody structure give the best chance of contact.
How do you catch Suckermouth Catfish?
Anglers in Brazil rarely target suckermouth catfish deliberately. Most encounters happen while bottom fishing for other species, with natural baits fished on or near rocky or woody substrate in slower river sections.
What do Suckermouth Catfish eat?
Primarily algae scraped from hard surfaces, plus detritus and small invertebrates, this is a bottom scavenger, not a predator, so conventional lures won't draw strikes the way they would for a tucunaré or dourado.
Where do Suckermouth Catfish live?
Native to northeastern Brazil and the coastal river drainages of the Guianas, this is where the species genuinely belongs, not an introduction. Lives in tropical freshwater: rivers, streams, and their associated pools, typically over rocky, sandy, or woody bottom where algae and detritus accumulate.
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