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

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