male of great diving beetle, dytiscus marginalis watches for prey hiding in dense hornwort vegetation, wide-spread wild freshwater

adult animal aqua aquarium background beetle behaviour biotic biotope bug clear closeup coldwater dangerous decorative dense display diving driftwood dytiscus eco ecological ecology endemic europe european fauna fish fishkeeping fresh freshwater great grey hiding hornwort hunt hunter insect lake lakes look macro male marginalis natural nature predator prey protection tank temperate typical underwater vegetation watch watches water weed widespread wild