Productive areas are found where structure and current create ambush points. Confluences where the Rio Mercedes meets smaller tributaries or streams are always productive, as they funnel baitfish. Deep pools adjacent to sandbars or undercut banks are prime locations for large Tucunaré and catfish. Areas with submerged timber, fallen trees, and root systems along the banks hold Traíra and Peacock Bass. The numerous lagoons and "furos" (connecting channels) that form off the main river, especially in the lower sections, are hotspots during the dry season when they hold trapped concentrations of fish.