Peixe-rei
Peixe-rei are slender, silver-sided fish of the family Atherinopsidae found in the lagoons, estuaries, and coastal waters of far southern Brazil. Several species overlap here — O. humensis and O. mirinensis in the Patos-Mirim lagoon complex, O.
argentinensis along the South Atlantic coast. Small but abundant, they draw both recreational and commercial fishing pressure in Rio Grande do Sul.
Scientific Name: Odontesthes argentinensis
Also known as Peixe-rei, silverside, peixe-rei-do-mar (O. argentinensis), peixe-rei-de-água-doce
- Elongated, slender body with a distinctive silver lateral band running the full length of the flank — the most reliable field mark.
- Small mouth, fine teeth, and large eyes relative to head size; back is pale olive-green to translucent, belly silvery-white.
- Most Brazilian specimens run 15–25 cm; O. humensis reaches up to 35 cm and around 436 g at maximum recorded size.
- Multiple species are nearly identical in the hand — lateral scale counts (52–60 in the lateral series) and predorsal scale counts help separate them, but location is usually the best clue.
What to know
Habitat Distribution
- Native to far southern Brazil; the core range covers the Lagoa dos Patos and Lagoa Mirim lagoon complex in Rio Grande do Sul, plus the adjacent South Atlantic coast.
- O. argentinensis is a coastal-marine and estuarine species distributed along the South Atlantic shore from southern Brazil south into Argentina.
- O. humensis and O. mirinensis are freshwater to brackish species tied to the Patos-Mirim system and the Río Uruguay and Río Negro drainages.
- Benthopelagic in habit — they move through the water column but are closely associated with the bottom in temperate, well-oxygenated water.
Key Locations
- Lagoa dos Patos, Rio Grande do Sul — the largest coastal lagoon in South America and the heart of the Brazilian peixe-rei fishery.
- Lagoa Mirim, on the Brazil-Uruguay border — home to O. humensis and the newly described O. mirinensis, both endemic to this lagoon complex.
- South Atlantic coast of Rio Grande do Sul — coastal beaches and estuarine inlets where O. argentinensis is targeted by shore anglers.
Specific Spots
- Shallow margins and sandy flats of Lagoa dos Patos and Lagoa Mirim, where peixe-rei school and feed near the surface during calm conditions.
- Estuarine channels and tidal inlets along the Rio Grande do Sul coast, where O. argentinensis moves with tidal flow chasing small invertebrates.
- Mouths of tributary streams entering the lagoon system, especially where current concentrates food and draws feeding schools.
Peixe-rei FAQ
Answers from onWater's species guide.
What are the best lures and bait for Peixe-rei?
Micro-spoons and small spinners (2–5 g) in silver or gold are reliable across the lagoon and coastal fishery, the flash mimics the small baitfish and crustaceans peixe-rei chase.
What flies work for Peixe-rei?
Small Clouser Minnows (size 8–10) tied sparse in white or chartreuse imitate the tiny baitfish and shrimp peixe-rei feed on in estuarine and lagoon settings.
When is the best time to fish for Peixe-rei?
Autumn and winter (March–August) tend to concentrate fish in the lagoon system as water temperatures drop and schools tighten. Spring (September–November) brings spawning activity in coastal and estuarine shallows, with fish moving into accessible shallow water.
How do you catch Peixe-rei?
Most anglers in southern Brazil fish peixe-rei from shore or small boats along the margins of Lagoa dos Patos and the coastal estuaries, using light spinning gear with small lures or shrimp under a float. Locating active schools near the surface at dawn or dusk is the key to consistent action.
What do Peixe-rei eat?
Primarily small invertebrates, zooplankton, aquatic insects, and tiny crustaceans. In estuarine and coastal settings, small shrimp and amphipods are key forage. Small jigs, micro-spoons, and live or fresh shrimp all match this feeding profile.
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