Matrinxã
Brycon gouldingi is a matrinxã endemic to the Rio Tocantins basin in Brazil. A mid-sized characin topping out around 2. 6 kg, it draws anglers with fast, acrobatic surface strikes and schooling behavior that can produce rapid-fire action.
It's also a first-class food fish prized by riverside communities throughout the Tocantins-Araguaia drainage.
Scientific Name: Brycon gouldingi
Also known as Matrinchã, Jatuarana, Matrinchão
- Silvery, torpedo-shaped body typical of the Brycon genus — deep-chested with a forked tail built for speed in current.
- Firm, orangey-tinted flesh visible when cleaned; a useful field indicator when distinguishing it from other silver characins in the same water.
- Reaches roughly 47–48 cm in length; published maximum weight is 2.6 kg, though related Brycon species in nearby basins run larger.
- Distinguished from close relatives by the proportions of the fifth infraorbital bone — a detail for taxonomists, but worth noting since several Brycon species share the same rivers.
What to know
Habitat Distribution
- Endemic to the Rio Tocantins basin in Brazil — this is its home water and the only basin where B. gouldingi is confirmed.
- Adults favor blackwater and clearwater tributaries; younger fish are more commonly found on whitewater floodplains during high water.
- During low water, schools move into the lower reaches of terra firme streams, holding in pools where current slows.
- A migratory species — it makes medium-distance spawning and dispersal runs, so fish move through the system seasonally rather than staying put year-round.
Key Locations
- Rio Tocantins basin — the only confirmed native range for B. gouldingi; the main river and its tributaries are the primary fishery.
- Rio Tapajós — the broader Tapajós drainage is noted as productive matrinxã water, though related Brycon species may be involved there.
- Terra firme stream pools within the Tocantins-Araguaia drainage hold concentrations of fish during the low-water season.
Specific Spots
- Shaded banks under overhanging trees in faster current — schools use the shade as cover and intercept fruits, insects, and seeds falling from the canopy.
- Pool tailouts and current breaks in terra firme streams during low water, where fish stack up and feed actively.
- Near structure — submerged timber, root tangles, and rocky outcrops — where the fish hold tight and won't chase a presentation far, so accuracy matters.
Matrinxã FAQ
Answers from onWater's species guide.
What are the best lures and bait for Matrinxã?
Small inline spinners are the most consistently effective hardware, the flash and vibration trigger strikes from schooling fish even when they're not actively surface feeding.
What flies work for Matrinxã?
Large terrestrial patterns are the go-to: Chernobyl Ants and similar foam-bodied flies imitate the beetles, ants, and grasshoppers that fall from bankside vegetation and make up a big part of the fish's surface diet.
When is the best time to fish for Matrinxã?
Rising water (roughly October–January): spawning migrations begin, and fish are actively moving through the system, good for intercepting schools in river channels. Low water (roughly June–September): fish concentrate in pools in smaller tributaries, making them easier to locate and target with surface presentations.
How do you catch Matrinxã?
Most anglers work the shaded, overhanging banks from a small boat, casting surface lures or flies tight to structure where schools are holding in current.
What do Matrinxã eat?
Adults eat primarily fruits and seeds that fall into the water, plus insects, invertebrates, and occasional small fish, match this with surface presentations like poppers or large terrestrial fly patterns that land with a splat near overhanging vegetation.
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