The body of a Daphnia species is usually 1–5 mm (0.039–0.197 in) long, and is divided into segments, although this division is not visible. The head is fused, and is generally bent down towards the body with a visible no… See more

Daphnia is a large genus – comprising over 200 species – belonging to the cladoceran family Daphniidae. It is subdivided into several subgenera (Daphnia, Australodaphnia, Ctenodaphnia), but the division ha… See more

Daphnia species are normally r-selected, meaning that they invest in early reproduction, so have short lifespans. An individual Daphnia lifespan depends on factors such as temperature and the abundance of … See more

Most Daphnia species have a lifecycle based on "cyclical parthenogenesis", alternating between parthenogenetic (asexual) and sexual reproduction. For most of the growth season, females reproduce asexually. … See more

The diagram on the left shows the lifecycle of Pasteuria ramosa, a bacterial parasite of Daphnia. Susceptible hosts acquire the infection from spores in the sediment or in suspension. The parasite develops mainly in the host'… See more