Franco Banfi / Northern pike (Esox lucius) amongst Shining pondweed (Potamogeton lucens), Sion, Valais canton, southwestern Switzerland, Europe

Franco Banfi / Northern pike (Esox lucius) amongst Shining pondweed (Potamogeton lucens), Sion, Valais canton, southwestern Switzerland, Europe

Franco Banfi / Northern pike (Esox lucius) amongst Shining pondweed (Potamogeton lucens), Sion, Valais canton, southwestern Switzerland, Europe

Franco Banfi / Pondweed (Potamogeton lucens), Sion, Valais canton, southwestern Switzerland, Europe

Alex Hyde / Broad-leaved pondweed (Potamogeton natans) growing in moorland pool, with raindrops beading on the hydrophobic surface of the leaves. Peak District National Park, Derbyshire, UK. December.

Nick Upton / Broad-leaved pondweed (Potamogeton natans) in heathland pond. Dorset, England, UK. June.

Nick Upton / Common European toad toadlet (Bufo bufo) sitting on a Broad-leaved pondweed (Potamogeton natans) leaf in a pond, Dorset, UK, June.

Nick Upton / Pondweed leafhopper (Erotettix cyane) nymph resting on a leaf of Broad-leaved pondweed (Potamogeton natans), its sole host plant in a heathland pond, Dorset, UK, June. This tiny insect is one of the U...

Nick Upton / Pondweed leafhopper (Erotettix cyane) adult resting on a Broad-leaved pondweed (Potamogeton natans) leaf, its sole food plant, in a heathland pond, Dorset, UK, June. This tiny insect is one of the UK'...

Michel Roggo / Northern pike (Esox lucius) amongst Shining pondweed (Potamogeton lucens) on tbed of Lake Neuchatel, Switzerland, September. Photographed for The Freshwater Project.

Michel Roggo / Northern pike (Esox lucius) amongst Shining pondweed (Potamogeton lucens). Lake Neuchatel, Switzerland, September. Photographed for The Freshwater Project.

Willem Kolvoort / Common toad (Bufo bufo) tadpoles amongst Perfoliate pondweed (Potamogeton perfoliatus) in ditch. Netherlands. May.