Predaceous Diving Beetles (Dytiscidae)

Diving beetles, whose bodies are generally flattened or not very convex, with long, bristle-fringed, and oar-shaped posterior legs, are particularly well adapted to their aquatic habits.

Thermonectes marmoratus. ETATS-UNIS, 1999.Dytiscus marginalis. FINLANDE, 1996.Dytiscus marginalis. TCHECOSLOVAQUIE, 1962.

Diving beetles live in stagnant or running, clear or muddy, sunny or shady waters of pools, ponds, lakes or rivers.

Diving beetles live entirely in water but they must return to the surface periodically to renew the air bubble that they keep under their elytra.  This is how the adult diving beetles breathe. 

Dytiscus latissimus. TCHECOSLOVAQUIE, 1992.Dytiscus marginalis. YOUGOSLAVIE, 1966.

They are ferocious predators feeding on small animals, worms, shellfish, and larvae and adults of insects. The greatest species also attack young frogs, tritons [??] and small fishes.

Like the adults, the larvae live exclusively in water and are extremely carnivorous.

Dytiscus marginalis. POLOGNE, 1999.

Adult and larva