water Article Diets and Trophic Structure of Fish Assemblages in a Large and Unexplored Subtropical River: The Uruguay River Anahí López-Rodríguez 1,2,3,*, Ivana Silva 2,3, Sunshine de Ávila-Simas 4, Samanta Stebniki 1, Rodrigo Bastian 5, Marthoni Vinicius Massaro 5 , Joaquin Pais 2,3, Giancarlo Tesitore 1, Franco Teixeira de Mello 1, Alejandro D’Anatro 2, Nicolas Vidal 1,2, Mariana Meerhoff 1, David A. Reynalte-Tataje 5, Evoy Zaniboni-Filho 4 and Iván González-Bergonzoni 3,6,* 1 Departamento de Ecología y Gestión Ambiental CURE, Universidad de la República, Tacuarembó s/n, 20000 Maldonado, Uruguay 2 Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Iguá 4225, Malvín Norte, 11400 Montevideo, Uruguay 3 Departamento de Ecología y Biología Evolutiva, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay 4 Laboratório de Biologia e Cultivo de Peixes de Água Doce (LAPAD), Departamento de Aquicultura, Universidade Federal de Santa Catarina (UFSC), 88066-260 Florianópolis, SC, Brazil 5 Campus Cerro Largo, Universidade Federal da Fronteira Sul, Av. Jacob Reinaldo Haupenthal, 1580, 97900-000 Cerro Largo, RS, Brazil 6 Departamento del Agua, CENUR Litoral Norte Universidad de la República, Ruta 3 Km 363, 60000 Paysandú, Uruguay * Correspondence:
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[email protected] (I.G.-B.) Received: 11 April 2019; Accepted: 28 June 2019; Published: 4 July 2019 Abstract: The Neotropics represent a hotspot for freshwater biodiversity with vast number of fish species of scarce ecological knowledge. This hold true for the Uruguay River, where fish assemblages and their diets remain unexplored.