Great Diving Beetle

• fisiologíaIt stores a bubble of air under its wing cases, which lets it breathe underwater for long spells while it hunts small invertebrates.
• Its larva, known as the water tiger, has hollow jaws with which it injects digestive enzymes into its prey and then sucks out the liquefied tissue.
• It flies between ponds at night, and sometimes mistakes the gleam of a wet roof or a dark car for the surface of the water.
• It breathes from a tank. It rises to the surface back first, pokes the tip of its abdomen out and stores a bubble of air beneath its elytra, which serves it both as a reserve and as a physical gill: oxygen from the water diffuses into the bubble while it dives.
• It is a fearsome predator for its size: it attacks tadpoles, insect larvae and small fish, and can kill prey larger than itself.
• The larva is even more voracious and is known as the water tiger. It has hollow mandibles through which it injects digestive enzymes and then sucks up the liquefied prey.
• The male's front legs are fitted with suckers with which it grips the female's smooth carapace during mating; she usually has grooved elytra, and it has been proposed that those grooves are a counter-adaptation to make this harder.
• It flies well, mostly at night, and colonises new ponds. It sometimes mistakes shiny surfaces such as car roofs or greenhouses for water and lands on them.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat & environment

Ponds, pools and still, vegetated backwaters

Sources consulted: Natural History Museum de Londres; Buglife; Bergsten y Miller (2007), PLOS ONE