Productive areas are often found near structural features that provide ambush points for predators. These include submerged logs, fallen trees (known as "galhadas"), riverbank undercuts, lagoon entrances, and the mouths of smaller tributaries. Areas with current breaks, such as behind islands or in eddies, are also prime locations. The confluence of the Rio Ajarani with the Rio Branco can be a particularly productive zone where different currents and food sources converge.