title: Molecular comparisons of freshwater and marine isolates of the same morphospecies of heterotrophic flagellates.
abstract: Heterotrophic flagellates are key components of all ecosystems. Understanding the patterns of biodiversity of these organisms is thus particularly important. Here we analyzed the intraspecific diversity of 10 morphospecies of heterotrophic flagellates comprising representatives of the Apusozoa (2 morphospecies) and Kinetoplastea (8 morphospecies), all belonging to the most common flagellates with worldwide distribution. Most morphospecies showed a mixing of lineages isolated from diverse habitats, indicating that some lineages of these morphospecies had been able to colonize different habitats several times. Furthermore, our results revealed remarkable levels of genetic divergence within most of the morphospecies studied, underlining the difficulty of correctly determining species by means of morphology alone. Many cryptic or pseudocryptic species seem to occur. Our results revealed clear divergence between marine and freshwater lineages of the morphospecies Ancyromonas sigmoides, showing that freshwater lineages have not been able to colonize marine environments and marine lineages have not been able to colonize freshwater environments for a long time.
authors.affiliation: Department of General Ecology and Limnology, Zoological Institute, University of Cologne, 50931 Cologne, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Scheckenbach
authors.forename: Claudia
authors.initials: C
authors.lastname: Wylezich
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Mylnikov
authors.forename: Markus
authors.initials: M
authors.lastname: Weitere
authors.forename: Hartmut
authors.initials: H
authors.lastname: Arndt
mesh_terms: D000818:Animals; D001483:Base Sequence; D044822:Biodiversity; D019976:Cloning, Organism; D056890:Eukaryota / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005618:Fresh Water; D014644:Genetic Variation; D008969:Molecular Sequence Data; D012337:RNA, Ribosomal, 18S / Q000032:analysis* / Q000235:genetics; D012623:Seawater
chemical_list: D012337:RNA, Ribosomal, 18S