Smooth Weakfish

Habitat Distribution

• Native to Brazil — present along the entire coast from the Amazon estuary and the states of Amapá, Pará, and Maranhão in the north down to Santos in the southeast.
• Lives on mud and sand bottoms in estuaries, surf zones, and shallow coastal waters, typically from the surface down to about 50 m, most commonly shallower than 25 m.
• Tolerates brackish and marine conditions; in Sepetiba Bay (Rio de Janeiro) it concentrates in the outer bay where salinity averages around 30 ppt.
• Particularly abundant in the northern coast estuaries of Amapá, Pará, and Maranhão, and in southeastern bays such as Sepetiba Bay and around Rio de Janeiro.

Key Locations

• Amazon Estuary and the northern coast (Amapá, Pará, Maranhão) — the heart of Brazil's commercial pescada fishery, with high catch volumes and active artisanal fleets.
• Sepetiba Bay, Rio de Janeiro — one of the most studied populations; the outer bay zone holds concentrations of this species year-round.
• Rio de Janeiro state coast — accounted for roughly 38% of southeastern Brazil's landings in documented years, making it a consistent recreational and commercial area.
• Todos os Santos Bay, Bahia — identified as a key fishery location for the species along the northeastern coast.

Specific Spots

• Muddy or sandy estuary channels — the lateral line extends into the tail fin, giving this fish exceptional vibration detection in turbid water, so it holds where current concentrates baitfish over soft bottom.
• Surf zone troughs and beach gutters, where wave action stirs up small invertebrates and disoriented baitfish along the bottom.
• Outer bay edges and drop-offs where polyhaline water meets shallower flats — in Sepetiba Bay, larger fish concentrate in the outer zone rather than shallow inner areas.
• Schools sort by size; bigger fish tend to hang just outside tighter schools of smaller individuals, so working the perimeter of a marked school is worth the effort.