WATER BOATMAN

any insect of the family Corixidae (order Heteroptera), with over 300 species. The water boatman has a flat, boat-shaped body and long, fringed, oarlike hindlegs. Members of this cosmopolitan family, usually less than 13 mm (0.5 inch) long, occur as high as the Himalayas, as deep as Death Valley, and in fresh, brackish, and salt waters. The water boatman is lighter than water; it generally attaches itself to vegetation at the bottom of a pond or stream and breathes from an envelope of air stored around its body and under its wings. Oxygen inspired by the insect from the bubble is replaced by diffusion from the water; carbon dioxide expired into the bubble is extracted by dissolution in the water. The insect swims with rapid, jerking movements; unlike many other heteropterans, it has a soft beak and cannot bite. When feeding, it scoops up algae and other small organisms with its spoon-shaped, fringed front legs. Eggs are usually deposited on underwater vegetation. Most males have stridulatory organs, rough areas on the forelegs that make a chirping sound when rubbed together.