English: The giant otter (Pteronura brasiliensis) known as "Anjo", one of a group of fourteen wild otters residing at Lago Grande, in Cantão State Park, in the Araguaia wetlands of central Brazil. This picture was taken by researchers from the Instituto Araguaia, which has been studying this particular group of otters in Cantão since 2010. The individuals are identified by the pattern of white marks on their throat, which the otters themselves use to recognize each other - hence their habit of displaying their throats whenever they meet a stranger, as the animal in the picture is doing.