Corixidae

Corixidae is a family of aquatic insects in the order Hemiptera that inhabit ponds and slow moving streams, where they swim near the bottom. There are about 500 known species worldwide, in 33 genera, including the genus Sigara.

Members of the Corixidae are known in the United States as water boatmen, a term that is sometimes used in the United Kingdom for Notonecta glauca, a bug of a different family, Notonectidae, and Corixa punctata is the "lesser water boatman".

Morphology and ecology

Corixidae generally have a long flattened body up to 13 millimetres (0.5 in) long and have extremely fine dark brown or black striations marking the wings. They have four long rear legs and two short front ones. The hind legs are covered with hairs and shaped like oars, hence the name "water boatman". Their front legs are scoop shaped at the tip. They also have a triangular head with short, triangular mouthparts. Corixidae dwell in slow rivers and ponds, as well as some household pools.

Unlike their relatives the backswimmers, who swim upside down near the surface of the water, Corixidae swim right side up near the bottom of ponds or streams. It is easy to tell the two types of insects apart simply by looking at where the insect is in the water and whether it is swimming upside down or not.