1. School of Natural Resources and Environment; University of Florida; 103 Black Hall Box 116455 Gainesville Florida 32611 U.S.A
2. Fisheries and Aquatic Sciences Program; School of Forest Resources and Conservation; University of Florida; 7922 NW 71st Street Gainesville Florida 32653 U.S.A
3. Instituto Nacional de Pesquisas da Amazônia; INPA/Laboratório de Mamíferos Aquáticos; Avenida André Araújo 2936 Manaus Amazonas 69060-001 Brazil
4. Centre for Remote Environments; University of Dundee; DCA Dundee DD1 4DK United Kingdom