Rio Jauru is a significant river flowing through the state of Mato Grosso in western Brazil, serving as one of the primary right-margin tributaries of the rio Paraguay. The river drains into the vast Pantanal floodplain — one of the world's largest tropical wetlands, covering approximately 140,000 km² — and is subject to the region's characteristic alternating wet and dry seasons. This seasonal flooding cycle is the defining ecological force shaping the river's fishery, as the Pantanal's rhythmic pulse of water drives fish behavior, movement, and abundance throughout the year. The rio Jauru's waters carry sediments that are deposited across the floodplain during flood events, creating a rich, productive aquatic environment that supports a diverse array of fish species typical of the upper rio Paraguay basin.