Some free-living flagellates (protista) from anoxic habitats

Thirty five species of fi ce-living anaerobic flagellates from freshwater and coastal sediments from Danish and Australian sites are reported. These belong to the genera Ancyromonas, Barthelona n. gen., Bodo, Cafeteria, Carpediemonas, Cercomonas, Chilomastix Chilomonas, Dimastigella, Goniomonas, Heteromita, Jakoba Mastigamoeba, Monotrichomonas n. gen., Paraphysomonas, , Percolomonas, Pseudotrichomonas, Quasibodo Quasibodo n. gen., Rhabdomonas, Rhynchobodo, Rhynchomonas, Salpingocca, Spumella, Trepomonas and Trimastix. Six new species are described, Barthelona vulgaris, Jakoba incarcerata, Mastigamoeba punctachora, Monotrichmonas carabina, Quasibodo laughtoni and Trimastix inaequalis. . The composition of the communities encountered under anoxic conditions overlaps with communities observed in aerobic environments and includes species of hetoroloboseids, kinetoplastids, euglenids, jakobids, stramenopiles, cercomonads, cryptomonads and choanoflagellates - all of which are mitochondriate. About half of the flagellates observed lack classical mitochondria, or belong to known amitochondriate groups. These taxa are assignable to the pelobionts, retortamonads, diplomonads, trichomonads, and to the genera Trimastix and Carpediemonas. Some taxa observed during this study have no clear identity and further study is necessary. This work confirms the existence of many poorly understood anaerobic flagellates, the study of which could increase our understanding of the pattern of mitochondrial gain and/or loss among extant eukaryotes, as well as the operation of anoxic ecosystems.