Jan Hamrsky / Diving beetle (Colymbetes fuscus) close up head portrait. Europe, June. Controlled conditions.

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) portrait, Europe, September, controlled conditions

Michael Durham / Diving Beetle (Cybister fimbriolatus) jumping into water, photographed with a high-speed camera, central Texas

Jan Hamrsky / Diving beetle larva (Platambus maculatus), Europe, February, controlled conditions

Will Watson / Head on view of Diving beetle (Cybister lateralimarginalis) resting among Bladderwort (Utricularia sp.) captive conditons, Belgium.

Will Watson / Diving beetle (Graphoderus cinereus) among Bladderwort (Utricularia sp.), captive, Belgium

Robert Thompson / Great diving beetle (Dytiscus marginalis) larva, Montiaghs Moss NNR, County Antrim, Northern Ireland, UK.

Will Watson / Diving Beetle (Rhantus exsoletus), Moccas Park National Nature Reserve, Herefordshire, England.

Will Watson / Diving bettle (Agaubus bipustulatus) taking air, Captive, Carmarthenshire, Wales, UK. July.

Will Watson / Diving Beetle (Colymbetes fuscus) resting on submerged log, captive, Herefordshire, England.

Will Watson / Diving beetle (Graphoderus cinereus) with Ciliates, Moccas Park, National Nature Reserve, Herefordshire, England, UK. Vulnerable species.

Will Watson / Diving beetle (Graphoderus cinereus) with Ciliates, Moccas Park, National Nature Reserve, Herefordshire, England, UK, June. Vulnerable.

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

John Abbott / Predacious diving beetle (Cybister fimbriolatus) swimming Williamson County, Texas, USA Controlled conditions. October

John Abbott / Predaceous diving beetle (Thermonectus basillaris), Tuscaloosa County, Alabama, USA Controlled conditions. July

Jan Hamrsky / Diving beetle (Platambus maculatus), Europe, August. Controlled conditions.

Jan Hamrsky / Diving beetle (Colymbetes fuscus), Europe, June. Controlled conditions.

Jan Hamrsky / Diving beetle larva (Cybister lateralimarginalis), Europe, May. Controlled conditions.

Jan Hamrsky / Diving beetle larva (Cybister lateralimarginalis), Europe, May. Controlled conditions.

Jan Hamrsky / Diving beetle (Cybister lateralimarginalis), Europe, May. Controlled conditions.

Jan Hamrsky / Diving beetle (Cybister lateralimarginalis), Europe, May. Controlled conditions.

Will Watson / Black belly diving beetle (Dytiscus semmisulcatus), Cheshire, England, UK, July. Captive.

MYN / Niall Benvie / Great diving beetle (Dytiscus marginalis) Burgundy, France. April.

MYN / Niall Benvie / Great diving beetle (Dytiscus marginalis) Burgundy, France. April.

MYN / Niall Benvie / Great diving beetle (Dytiscus marginalis) underwater, Burgundy, France. April.

MYN / Niall Benvie / Great diving beetle (Dytiscus marginalis) underwater, Burgundy, France. April.

MYN / Niall Benvie / Great diving beetle (Dytiscus marginalis) Burgundy, France. April.

MYN / Paul van Hoof / Great diving beetle (Dytiscus marginalis) larva, June, The Netherlands, Meetyourneighbours.net project

Will Watson / Water beetle (Rhantus suturalis) Shropshire, England. Captive. May 2014.

Jussi Murtosaari / Great diving beetle (Dytiscus marginalis) diving in aquarium, Kumlinge, Ahvenanmaa / Aland Islands Archipelago, Finland. November

Jussi Murtosaari / Great diving beetle (Dytiscus marginalis) in aquarium, Kumlinge, Ahvenanmaa / Aland Islands Archipelago, Finland. November

Jussi Murtosaari / Great diving beetle (Dytiscus marginalis) Photographed in aquarium, Kumlinge, Ahvenanmaa / Aland Islands Archipelago, Finland. November

Jan Hamrsky / Diving beetle (Graphoderus bilineatus) larva, head detail. Europe, June, controlled conditions.

Jan Hamrsky / Diving beetle (Graphoderus bilineatus) larva breathing at surface, Europe, June, controlled conditions.

Jan Hamrsky / Diving beetle (Graphoderus bilineatus) larva breathing at surface, Europe, June, controlled conditions.

Jan Hamrsky / Water beetle (Laccophilus sp) taking air at the surface, January, Europe, controlled conditions.

MYN / Niall Benvie / Field studio composite of amphibians, fish, and aquatic invertebrates from Preporche, Burgundy, France, April. meetyourneighbours.net project

MYN / Krista Schlyer / Diving beetle (Dytiscidae sp.) larva, Lily Lake, Estes Park, Colorado, USA. August. Meetyourneighbours.net project.

Ann & Steve Toon / British diving beetles (Dytiscus sp.), museum specimens, Tyne and Wear Archives and Museums

Will Watson / Female Great diving beetle (Dytiscus circumflexus) at surface to breath, UK, captive.

Will Watson / Female Great diving beetle (Dytiscus circumflexus) view of underside with cloacal sperm plug from previous mating, UK, captive.

Will Watson / Male Great Diving Beetle (Dytiscus marginalis) taking in air, captive, Essex, England.

Will Watson / Female Great diving beetle (Dytiscus circumflexus), resting on Hornwort, captive, UK.

Will Watson / Female Great diving beetle (Dytiscus circumflexus), resting on Hornwort, UK, captive.

Will Watson / Female Black Belly (Dytiscus semisulcatus) at surface for air, Llyn Heilyn, Radnorshire, Wales.

Jan Hamrsky / Lesser diving beetles (Acilius sulcatus) mating pair, Europe, May, controlled conditions

Jan Hamrsky / Lesser diving beetles (Acilius sulcatus) mating pair, Europe, May, controlled conditions

Jan Hamrsky / Lesser diving beetles (Acilius sulcatus) mating pair, Europe, May, controlled conditions

Jan Hamrsky / Lesser diving beetle (Acilius sulcatus) male, Europe, May, controlled conditions

Jan Hamrsky / Lesser diving beetle (Acilius sulcatus) refilling its air supply by the surface, male, Europe, May, controlled conditions

Jan Hamrsky / Diving beetle (Agabus sturmii) refilling its air supply by the surface, Europe, May, controlled conditions

Jan Hamrsky / Diving beetle (Agabus sturmii) Europe, May, controlled conditions

Jan Hamrsky / Diving beetles (Graphoderus bilineatus) female (right) and male (left) Europe, August, controlled conditions

Jan Hamrsky / Diving beetle (Graphoderus bilineatus) male, Europe, August, controlled conditions

Jan Hamrsky / Diving beetles (Graphoderus bilineatus) female (left) and male (right) Europe, August, controlled conditions

Jan Hamrsky / Diving beetle (Graphoderus bilineatus) refilling the air supply by the surface, female, Europe, August, controlled conditions

Jan Hamrsky / Diving beetle (Graphoderus bilineatus) refilling the air supply by the surface, male, Europe, August, controlled conditions

Jan Hamrsky / Diving beetle (Graphoderus bilineatus) cleaning its antennae, female, Europe, August, controlled conditions

Jan Hamrsky / Diving beetle larva (Graphoderus bilineatus) Europe, June, controlled conditions

Jan Hamrsky / Great diving beetle larva (Dytiscus marginalis) head detail, Europe, June, controlled conditions

Jan Hamrsky / Great diving beetle larva (Dytiscus marginalis) with dragonfly nymph prey, Europe, June, controlled conditions

Jan Hamrsky / Great diving beetle larva (Dytiscus marginalis) with dragonfly nymph prey, Europe, June, controlled conditions

Jan Hamrsky / Great diving beetle larva (Dytiscus marginalis) breathing by the water surface, Europe, June, controlled conditions

Wild Wonders of Europe / Lundgren / Water beetle (Dytiscidae) swimming just under the surface at night, Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Water beetle nymph (Dytiscidae) attacking a large dragonfly nymph, Danube Delta, Romania, June. Ph

Wild Wonders of Europe / Lundgren / Water beetle (Dytiscidae) nymph, Danube Delta, Romania, June.

Michael Quinton / Diving Beetle (Dytiscidae) larva with caddis fly larva prey, Alaska

Michael Quinton / Diving Beetle (Dytiscidae) larva, Alaska

Michael Quinton / Diving Beetle (Dytiscidae) larva with mosquito larva prey, Alaska

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) female, Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) hiding in freshwater red algae (Batrachospermum moniliforme) Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) female, Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) hind oar-like leg detail, Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) refilling its air supply under the wing cases, Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) female, Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) refilling its air supply under the wing cases, Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) refilling its air supply under the wing cases, Europe, September, controlled conditions

Jan Hamrsky / Great diving beetle larva (Dytiscus marginalis) feeding on tadpole, Europe, May, controlled conditions

Sven Zacek / Waterbugs (Dytiscidae) on lake surface. Southern Estonia, August.

MYN / David Hunter / Diving Beetle (Dytiscidae) larvae on underside of water surface (hanging upside down) in vernal pool, California, USA, July. meetyourneighbours.net project

Jan Hamrsky / Water Beetle (Rhantus suturalis: Dytiscidae) with breathing bubble visible under carapace. Europe, May.

Jan Hamrsky / Water Beetle (Hyphydrus ovatus: Dytiscidae) at surface. Europe, May.

Jan Hamrsky / Water Beetle (Platambus maculatus: Dytiscidae). Europe, July.

Jan Hamrsky / Water Beetle (Hyphydrus ovatus: Dytiscidae) with breathing bubble on abdomen. Europe, May.

Jan Hamrsky / Water Beetle (Platambus maculatus: Dytiscidae). Europe, July.

Jan Hamrsky / Water Beetle (Platambus maculatus: Dytiscidae) with breathing bubble visible on abdomen. Europe, July.

Jan Hamrsky / Water Beetle (Platambus maculatus: Dytiscidae). Europe, July.

Jan Hamrsky / Water Beetle (Hyphydrus ovatus: Dytiscidae). Europe, May.

Jan Hamrsky / Water Beetle (Rhantus suturalis: Dytiscidae). Europe, May.

Suzi Eszterhas / Sunburst / Marbled diving beetle (Thermonectus marmoratus) swimming underwater with air bubble, Red Corral Ranch, Texas, USA

Suzi Eszterhas / Sunburst / Marbled diving beetle (Thermonectus marmoratus) swimming underwater, with air bubble, Corral Ranch, Texas, USA

Suzi Eszterhas / Sunburst / Marbled diving beetle (Thermonectus marmoratus) underwater, with air bubble, Corral Ranch, Texas, USA

ZSSD / Sunburst Diving Beetle (Thermonectus marmoratus) underwater, native to North America

ZSSD / Sunburst Diving Beetle (Thermonectus marmoratus) underwater with air bubble, native to North America

SINCLAIR STAMMERS / Water beetle (Nebrioporus elegans) Herefordshire, UK

SINCLAIR STAMMERS / Water beetle (Graptodytes pictus) Herefordshire, UK