Carpediemonas is genus of Metamonada, and belongs to the group Excavata. This organism is a unicellular flagellated eukaryote that was first discovered in substrate samples from the Great Barrier Reef. Carpediemonas can be found in anaerobic intertidal sediment, where it feeds on bacteria. A feature of this species is the presence of a feeding groove, a characteristic of the excavates. Like most other metamonads, Carpediemonas does not rely on an aerobic mitochondrion to produce energy. Instead, it contains hydrogenosomes that are used to produce ATP. This organism has two flagella: a posterior one used for feeding on the substrate, and an anterior one that moves in a slower sweeping motion. Carpediemonas is assigned to the fornicates, where similar Carpediemonas-like organisms are used in researching the evolution within excavates. Although Carpediemonas is a member of the metamonads, it is unusual in the sense that it is free-living and has three basal bodies. Etymology The name Carpediemonas originates from three Latin roots, with carpe meaning ‘seize’, die meaning ‘the day’, and the suffix of monas, indicating a unicellular organism. The organism was named after ‘carpe diem’, meaning ‘to seize the day’, in honour of the wife of one of the authors, who had recently died. History of Knowledge Carpediemonas was first discovered by Larsen and Patterson (1990) who identified it as a previously unidentified Percolomonas and provided the name Percolomonas membranifera. Larsen and Patterson treated this organism as a heterolobosean, because it would occasionally have four flagella and contain a longitudinal groove. However, they did not have any evidence that the non-dividing organisms had more than two flagella. The species also contained a pouch with threads that may be difficult to discern from flagella. Ekebom et al. (1996) then renamed the organism as Carpediemonas when it was found from substrate samples in the Great Barrier Reef and classified it as a metamonad. Additionally, a metabolic relationship of Carpediemonas with prokaryotic communities was found in Carpediemonas frisia. C. frisia was found to release biomolecules that have been predigested. Prokaryotic communities would rely on C. frisia for incompletely digested organic material and the oxidation of various biomolecules. On the other hand, C. frisia relies on the prokaryotic organism, Deltaproteobacteria, for its hydrogen oxidizing activity. Habitat and Ecology Carpediemonas can be found in anaerobic intertidal sediments, where it feeds on bacteria. It can be found co-existing with Cafeteria marsupialis in these anaerobic environments. Description of