Luke Massey / Giant otters (Pteronura brasiliensis) feed on a Golden dorado (Salminus brasiliensis) Pantanal, Brazil.

Ingo Arndt / European river otter {Lutra lutra} swimming, Europe

Ingo Arndt / Two European river otters {Luyra lutra} resting a on grass bank. Captive

Ingo Arndt / European river otters {Lutra lutra} Europe

SCOTLAND: The Big Picture / Eurasian otter (Lutra lutra) portrait, Scotland, UK, April.

SCOTLAND: The Big Picture / European river otter (Lutra lutra) female bringing octopus ashore for cub, Shetland, Scotland, UK, October.

SCOTLAND: The Big Picture / A family of otters rest on the intertidal seaweed. European river otter (Lutra lutra) Shetland, Scotland, UK, July.

SCOTLAND: The Big Picture / European river otter (Lutra lutra) cubs play fighting, Shetland, Scotland, UK, May.

Nick Hawkins / Neotropical river otter (Lontra longicaudis) in water, Nicoya Peninsula, Costa Rica, March 2015.

Tony Heald / Giant Otter (Pteronura brasiliensis) adult with young in water, Pantanal, Brazil

Bence Mate / European otter (Lutra lutra) with fish prey, with water splashing around, Kiskunsagi National Park, Hungary, July.

Bence Mate / European otter (Lutra lutra) shaking off water, Kiskunsagi National Park, Hungary, January.