Michel Loup / Four Pike (Esox lucius) and their reflections under the water surface, amongst Potamogeton sp pondweed in a mountain lake, Jura, France. Veolia Environnement Wildlife Photographer of the Year 2009 - W...

Michel Roggo / Pondweed (Potamogeton sp.) in channel of the Danube Delta, Romania, May 2015 . Photographed for The Freshwater Project

Kim Taylor / Raft spider (Dolomedes fimbriatus) female on leaf (Potamogeton sp) Surrey, England, September.

Chris Mattison / Broad-leaved pondweed (Potamogeton natans) growing among Sphagnum moss in a small pond in Woorgreens Nature Reserve, Gloucestershire, UK

Nick Upton / Broad-leaved pondweed (Potamogeton natans) flowering in a marshland pond, Devon, UK, June

Willem Kolvoort / Longleaf Pondweed (Potamogeton nodosus) River Ijesell, Holland. July.

Willem Kolvoort / Brook with Rigid Hornwort (Ceratophyllum demersum), Shining Pondweed (Potamogeton lucens) with Great Yellowcress (Rorippa amphibia) North Holland. June.

Wild Wonders of Europe / Lundgren / Current pulling weeds possibly Potamogeton sp, along riverbed, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Aquatic plant, possibly Potamogeton sp, in river current, Danube Delta, Romania, June.

Adrian Davies / Leaves of Bog Pondweed {Potamageton polygonifolius} New Bridge Marsh, Dartmoor, Devon, England

Niall Benvie / Pondweed {Potamogeton sp} Tansley bog, Beinn Eighe NNR, W Ross, Scotland

Willem Kolvoort / Broad leaved pondweed (Potamogeton sp) underwater in brook, Holland