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The Euglenozoa is a monophyletic group consisting of single-celled flagellates with very different modes of nutrition, including predation, osmotrophy, parasitism, and photoautotrophy. Predatory euglenozoans are phylogenetically widespread within the group and show a wide diversity of feeding apparatus structure, feeding strategies and prey preferences (Leander et al. 2001; Leander 2004). For instance, some predatory species prefer small prey such as bacteria (e.g., Bodo and Entosiphon); other species, such as Peranema and diplonemids frequently consume larger prey, such as other eukaryotic cells, by either engulfing them whole ( ‘true’ phagotrophy) or by piercing the prey cell and consuming the contents (myzocytosis). Most predatory euglenids are adapted to move and feed on surfaces and they are important components of the microbial biota in many surface sediments. Osmotrophic euglenozoans are heterotrophs that lack a feeding apparatus and absorb nutrients directly from their environments (e.g., Distigma and Rhabdomonas). Photoautotrophy is restricted to a specific subclade of euglenid euglenozoans and originated via secondary endosymbiosis between a eukaryovorous euglenid and a green algal cells (Gibbs 1978; Leander 2004, Leander et al. 2007) (e.g. see the third cell, starting from the left, in the title image). Parasitic (and commensalistic) euglenozoans appear to have evolved independently several times within the group (Simpson et al. 2002, 2006). One subgroup, the trypanosomatids (e.g. see right-hand cell in the title image), include the organisms that cause important human illnesses such as "sleeping sickness", leishmaniases, and Chagas’ disease. Euglenozoans, whether they are parasitic or photoautotrophic, share several derived cytoskeletal features associated with the flagellar apparatus and the feeding apparatus.