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

Jan Hamrsky / Great Diving Beetle (Dytiscus marginalis) larva feeding on small fish. Czech Republic. Controlled conditions.

Kim Taylor / Water beetles (Dytiscus marginalis) and (Acilius sulcatus) clustered around an air bubble trapped beneath the ice of a frozen pond, digitally enhanced, Surrey, England

Jane Burton / Great Diving Beetle {Dytiscus marginalis} female taking air at water surface, Surrey, England.

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

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

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.

Jan Hamrsky / Great silver water beetle (Hydrophilus piceus) female, Europe, May. Controlled conditions.

Jan Hamrsky / Great silver water beetle (Hydrophilus piceus) female, refilling its air store at water surface, Europe, May. Controlled conditions.