adult male of great diving beetle, dytiscus marginalis, wide-spread freshwater predator insect hunt for prey

adult aggressive algae animal aqua aquarium background beetle behaviour biotic biotope bug clear coldwater conditions controlled copy dangerous decorative display diving driftwood dytiscus eco ecological ecology endemic europe european fauna fish fishkeeping focus free fresh freshwater great hind hornwort hunt hunter insect lake leg look macro male marginalis natural nature predator prey protection river space tank temperate underwater vegetation water weed widespread wild