Leptodora

Leptodora is a genus containing two species of large, nearly transparent predatory water fleas. They grow up to long, with two large antennae used for swimming and a single compound eye. The legs are used to catch copepods that it comes into contact with by chance. Leptodora kindtii is found in temperate lakes across the Northern Hemisphere and is probably the only water flea species ever described in a newspaper; L. richardi is only known from eastern Russia. For most of the year, Leptodora reproduces parthenogenetically, with males only appearing late in the season, to produce winter eggs which hatch the following spring. Leptodora is the only genus in its family, the Leptodoridae, and suborder, Haplopoda.

==Description== Adults of Leptodora are the largest planktonic cladocerans native to North America; reports vary concerning the largest size, but adult females typically grow to long, but with some reports of females up to . They are about 98% transparent, as a defense against predation by fish. Lilljeborg notes: The female is transparent to such a high degree, literally "as clear as water", that her presence is often only given away by her movements. In bright sunlight, the shadow is normally seen before the animal itself. The male is similarly transparent. The abdomen is elongated, but the carapace is small and only covers the brood pouch.