Michel Roggo / Cichlids (Cichlidae) in Lake Malawi, Malawi, November. Photographed for The Freshwater Project.

Michel Roggo / Piraputanga (Brycon hilarii) and small Tetra fish (Hyphessobrycon sp.) Rio Olhio d'Agua, tributary of Rio da Prata, Serra da Bodoquena (Bodoquena Mountain Range), Mato Grosso do Sul, Brazil Novemb...

Michel Roggo / Chub (Squalius cephalus), on spawning ground Sava Bohinjka River, Slovenia June 2013 . Photographed for The Freshwater Project

Michel Poinsignon / Kingfisher (Alcedo atthis) male, after diving, taking off from water with fish, a Common Roach (Rutilus rutilus) Lorraine, France, August

Adrian Davies / Waterwheel plant (Aldrovanda vesiculosa) a carnivorous aquatic plant with Mosquito larva.

Franco Banfi / Young Stone sculpin (Paracottus knerii), on endemic sponge (Lubomirskia baicalensis), Lake Baikal, Siberia, Russia.

Alex Hyde / Green hydra (Hydra viridissima) found in a garden pond. Derbyshire, UK. September. Winner of the Hidden Britain Category of the British Wildlife Photographer of the Year Awards (BWPA) Competition 2017...