Corixidae

Corixidae is a family of aquatic insects in the order Hemiptera. They are found worldwide in virtually any freshwater habitat and a few species live in saline water. There are about 500 known species worldwide, in 55 genera, including the genus Sigara.
Members of the Corixidae are commonly known as lesser water boatmen: the term used in the United Kingdom to distinguish species such as Corixa punctata from Notonecta glauca, or greater water-boatman, an insect of a different family, Notonectidae.

Morphology and ecology

Corixidae generally have a long flattened body ranging from long. Many have extremely fine dark brown or black striations marking the wings. They tend to have four long rear legs and two short front ones. The forelegs are covered with hairs and shaped like oars, hence the name "water boatman". Their four hindmost legs have scoop- or oar-shaped tarsi to aid swimming. 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, Corixidae swim right side up. It is easy to tell the two types of insects apart simply by looking at the swimming position.
Corixidae are unusual among the aquatic Hemiptera in that some species are non-predatory, feeding on aquatic plants and algae instead of insects and other small animals. They use their straw-like mouthparts to inject enzymes into plants. The enzymes digest the plant material, letting the insect suck the liquified food back through its mouthparts and into its digestive tract. However, most species are not strictly herbivorous and can even be completely predatory, like those of the subfamily Cymatiainae. In fact, Corixidae have a broad range of feeding styles: carnivorous, detritivorous, herbivorous and omnivorous.
Some species within this family are preyed upon by a number of amphibians including the rough-skinned newt ''.
The reproductive cycle of Corixidae is annual. Eggs are typically oviposited on submerged plants, sticks, or rocks. In substrate limited waters, every bit of available substrate will be covered in eggs.

Genera

These 52 genera belong to the family Corixidae:Acromocoris Bode, 1953^gAgraptocorixa Kirkaldy, 1898^gArchaecorixa Popov, 1968^gArctocorisa Wallengren, 1894^{i c g b}Bakharia Popov, 1988^gBumbacorixa Popov, 1986^gCallicorixa White, 1873^{i c g b}Cenocorixa Hungerford, 1948^{i c g b}Centrocorisa Lundblad, 1928^{i c g}Corisella Lundblad, 1928^{i c g b}Corixa Geoffroy, 1762^{i c g}Corixalia Popov, 1986^gCorixonecta Popov, 1986^gCorixopsis Hong & Wang, 1990^gCristocorixa Popov, 1986^gCymatia Flor, 1860^{i c g b}Dasycorixa Hungerford, 1948^{i c g b}Diacorixa Popov, 1971^gDiapherinus Popov, 1966^gDiaprepocoris^{c g}Ectemnostegella Lundblad, 1928^gGazimuria Popov, 1971^gGlaenocorisa Thomson, 1869^{i c g b}Graptocorixa Hungerford, 1930^{i c g b}Haenbea Popov, 1988^gHeliocorisa Lundblad, 1928^gHesperocorixa Kirkaldy, 1908^{i c g b}Liassocorixa Popov, Dolling & Whalley, 1994^gLinicorixa Lin, 1980^gLufengnacta Lin, 1977^gMesocorixa Hong & Wang, 1990^gMesosigara Popov, 1971^gMorphocorixa Jaczewski, 1931^{i c g}Neocorixa Hungerford, 1925^{i c g}Neosigara Lundblad, 1928^gPalmacorixa Abbott, 1912^{i c g}Palmocorixa^bParacorixa Stichel, 1955^gParasigara Poisson, 1957^gPseudocorixa Jaczewski, 1931^{i c g}Ramphocorixa Abbott, 1912^{i c g b}Ratiticorixa Lin, 1980^gShelopuga Popov, 1988^gSiculicorixa Lin, 1980^gSigara Fabricius, 1775^{i c g b}Sigaretta Popov, 1971^gTrichocorixa Kirkaldy, 1908^{i c g b}Velocorixa Popov, 1986^gVenacorixa Lin Qibin, 1986^gVulcanicorixa Lin, 1980^gXenocorixa Hungerford, 1947^gYanliaocorixa Hong, 1983^g
Data sources: i = ITIS, c = Catalogue of Life, g = GBIF, b = Bugguide.net