Some free-living flagellates (protista) from anoxic habitats

Thirty five species of fi ce-living anaerobic flagellates from freshwater a nd coastal sediments from Danish and Australian sites are reported. These b elong to the genera Ancyromonas, Barthelona n. gen., Bodo, Cafeteria, Carpe diemonas, Cercomonas, Chilomastix Chilomonas, Dimastigella, Goniomonas, Het eromita, Jakoba Mastigamoeba, Monotrichomonas n. gen., Paraphysomonas, , Pe rcolomonas, Pseudotrichomonas, Quasibodo Quasibodo n. gen., Rhabdomonas, Rh ynchobodo, Rhynchomonas, Salpingocca, Spumella, Trepomonas and Trimastix. S ix new species are described, Barthelona vulgaris, Jakoba incarcerata, Mast igamoeba punctachora, Monotrichmonas carabina, Quasibodo laughtoni and Trim astix inaequalis. . The composition of the communities encountered under an oxic conditions overlaps with communities observed in aerobic environments and includes species of hetoroloboseids, kinetoplastids, euglenids, jakobid s, stramenopiles, cercomonads, cryptomonads and choanoflagellates - all of which are mitochondriate. About half of the flagellates observed lack class ical mitochondria, or belong to known amitochondriate groups. These taxa ar e assignable to the pelobionts, retortamonads, diplomonads, trichomonads, a nd to the genera Trimastix and Carpediemonas. Some taxa observed during thi s study have no clear identity and further study is necessary. This work co nfirms the existence of many poorly understood anaerobic flagellates, the s tudy of which could increase our understanding of the pattern of mitochondr ial gain and/or loss among extant eukaryotes, as well as the operation of a noxic ecosystems.