Common Water-Boatman

• Swimming on its back turns its world upside down: its belly, facing up, is dark, and its back, facing the bottom, is pale — exactly the reverse of almost every other aquatic animal.
• It carries a store of air clinging to the hairs of its abdomen and comes up periodically to renew it, which makes it buoyant and forces it to swim actively to stay under.
• Its defensive bite is painful to people, which is why in some places it is called the water wasp.
• It swims on its back — always, belly up. That is its defining trait, and it is what earns it the name backswimmer.
• And its colouration runs the opposite way to almost every other animal's: it has a dark belly and a pale back, because, as it swims upside down, that countershading still works just as it should, camouflaging it from above and from below.
• It detects its prey by the ripples they make when they fall into the water: the sensors on its legs and antennae let it pinpoint the spot where an insect has hit the surface.
• It carries air with it: it holds a film of air under its wings and along its abdomen, pinned in place by water-repellent hairs, which serves it as both a reserve and a physical gill.
• Its bite is painful, which is why in several languages it is called the water bee.
• It is a voracious predator of mosquito larvae, tadpoles and other aquatic invertebrates.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Ponds, pools and still backwaters with vegetation

Sexual maturity

Five nymphal instars spread over the summer; full nymphal development takes two to three months in favourable conditions

Gestation / incubation

The eggs, white and elongated, are stuck to or inserted into the stems and leaves of aquatic vegetation and have a micropylar end that allows gas exchange with the water

Sources consulted: Wikipedia (es): Notonecta glauca · UF/IFAS EDIS EENY-738 · Ficha de especie de Notonecta glauca (Balmert) · UF/IFAS EDIS EENY-738 (Briers 1998)