Fig. 1.

Schematic phylogenetic tree of the animals with a focus on Daphnia (in red). Daphnia are Cladocera, that form together with the Notostraca and Anostraca the Branchiopoda, formerly sometimes referred to as lower Crustaceans. Together with the Malacostraca, Copepoda, Cirripedia and some smaller taxa they form the Crustacea, now believed to be a paraphyletic taxon, because the Hexapoda are part of this clade, but not considered Crustaceans. Thus, Daphnia may be closer related to the model organism Drosophila than to a lobster. All of them are included in the Ecdysozoa, to which also the roundworms (Nematoda) belong. The tree was composed by taking various sources into account [24, 25, 127–130]. For animal pictograms see http://www.phylopic.org