Will Watson / Female Smooth Newt (Triturus / Lissotriton vulgaris) swimming amongst Hornwort (Ceratophyllum demersum) captive, UK

Will Watson / Emerald Damselfly (Lestes sponsa) nymph on Hornwort (Ceratophyllum demersum), captive, Carmarthenshire, Wales.

Will Watson / Common hawker nymph (Aeshna juncea) on Hornwort (Ceratophyllum demersum), captive, Breconshire, Wales.

Will Watson / Mud dweller beetle (Ilybius ater) at rest on Hornwort (Ceratophyllum demersum), Carmarthenshire, Wales. Captive.

Will Watson / Great crested newt (Triturus cristatus) male in breeding condition, amongst Soft hornwort (Ceratophyllum submersum), Herefordshire, England, UK, May. Captive.

Will Watson / Crucian Carp (Carassius carassius), amongst Hornwort (Ceratophyllum demersum), Worcestershire, England, UK, March. Captive, bred for re-stocking.

Will Watson / European chub (Squalius cephalus) amongst Hornwort (Ceratophyllum demersum), captive and bred for re-stocking, Worcestershire, England.

Will Watson / The Cherrystone Beetle (Hyphydrus ovatus) resting on Hornwort (Ceratophyllum demersum) Herefordshire, England. Captive.

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

Willem Kolvoort / Brook landscape with Rigid Hornwort (Ceratophyllum demersum), North Holland. June.

Wild Wonders of Europe / Lundgren / View looking out from underneath floating reedbed to a area of Soft hornwort (Ceratophyllum submersum) swaying in the current, tributary of the Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Pool frog tadpole (Pelophylax lessonae) in Soft hornwort (Ceratophyllum submersum) underwater, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Pool frog tadpole (Pelophylax lessonae) feeding on Soft hornwort (Ceratophyllum submersum) underwater, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Pool frog tadpole (Pelophylax lessonae) amongst Soft hornwort (Ceratophyllum submersum), underwater, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / School of Belica fish (Leucaspius delineatus) at the edge of a Soft hornwort carpet (Ceratophyllum submersum), Danube, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / School of Belica fish (Leucaspius delineatus) at the edge of a Soft hornwort (Ceratophyllum submersum), Danube, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Soft hornwort (Ceratophyllum submersum) in a small tributary of Danube, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Soft hornwort (Ceratophyllum submersum) in a small tributary to Danube, Danube Delta, Romania, June.

Will Watson / Kettle hole pool which is aquifer-fed pool with fluctuating water levels, with Soft hornwort (Ceratophyllum submersum), Herefordshire. UK, July 2013.

Will Watson / Perch (Perca fluviatilis) against backdrop of Hornwort (Ceratophyllum submersum) UK, captive

Will Watson / Great Diving Beetle (Dytiscus marginalis) female on Hornwort (Ceratophyllum demersum) UK, captive

Albert Lleal / Soft Hornwort (Ceratophyllum submersum) leaf showing chloroplasts and cell walls

Will Watson / Emperor dragonfly (Anax imperator) nymph on Hornwort (Ceratophyllum), captive, England, UK, June

Will Watson / Male Great Diving Beetle (Dytiscus marginalis) on Soft Hornwort (Ceratophyllum submersum). Captive. Herefordshire, UK, August.

Will Watson / The Lesser Water Boatman (Corixa punctata) resting on Soft Hornwort (Ceratophyllum submersum) in pond, captive, England.

Will Watson / Male Lesser Diving Beetle (Acilius sulcatus) on Hornwort (Ceratophyllum demersum) Herefordshire, England, UK

Will Watson / Three-spined Stickleback (Gasterosteus aculeatus) feeding on Horsehair Worm, amongst Soft Hornwort (Ceratophyllum submersum) in pond, captive, England, UK

Will Watson / Great diving beetle (Dytiscus circumflexus) on Soft Hornwort (Ceratophyllum submersum) in pond, captive, UK.

Will Watson / The underside of Great diving beetle (Dytiscus circumflexus) on Soft Hornwort (Ceratophyllum submersum) in pond, captive, UK.

Will Watson / Great Diving beetle (Dytiscus circumflexus) on Soft Hornwort (Ceratophyllum submersum) in pond, captive, UK.

Will Watson / Diving beetle (Colymbetes fuscus) on Hornwort (Ceratophyllum demersum), captive, England.

Will Watson / Female Smooth Newt (Triturus / Lissotriton vulgaris) with Hornwort (Ceratophyllum demersum) and Greater Spearwort (Ranunculus lingua), captive, England.

Willem Kolvoort / Rigid hornwort {Ceratophyllum demersum} with algae in the background, Lake Naarden, Holland

Georgette Douwma / Common frog (Rana temporaria) tadpoles feeding on Common garden snail (Helix aspersa) which has fallen in the water; small pond snails on its shell, London, England, UK. May.