title: Molecular phylogeny and taxonomic revision of the genus Wittrockiella (Pithophoraceae, Cladophorales), including the descriptions of W. australis sp. nov. and W. zosterae sp. nov.
abstract: Wittrockiella is a small genus of filamentous green algae that occurs in habitats with reduced or fluctuating salinities. Many aspects of the basic biology of these algae are still unknown and the phylogenetic relationships within the genus have not been fully explored. We provide a phylogeny based on three ribosomal markers (ITS, LSU, and SSU rDNA) of the genus, including broad intraspecific sampling for W. lyallii and W. salina, recommendations for the use of existing names are made, and highlight aspects of their physiology and life cycle. Molecular data indicate that there are five species of Wittrockiella. Two new species, W. australis and W. zosterae, are described, both are endophytes. Although W. lyallii and W. salina can be identified morphologically, there are no diagnostic morphological characters to distinguish between W. amphibia, W. australis, and W. zosterae. A range of low molecular weight carbohydrates were analyzed but proved to not be taxonomically informative. The distribution range of W. salina is extended to the Northern Hemisphere as this species has been found in brackish lakes in Japan. Furthermore, it is shown that there are no grounds to recognize W. salina var. kraftii, which was described as an endemic variety from a freshwater habitat on Lord Howe Island, Australia. Culture experiments indicate that W. australis has a preference for growth in lower salinities over full seawater. For W. amphibia and W. zosterae, sexual reproduction is documented, and the split of these species is possibly attributable to polyploidization.
authors.affiliation: School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand.
authors.forename: Christian
authors.initials: C
authors.lastname: Boedeker
authors.affiliation: Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, 98250, USA.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: O'Kelly
authors.affiliation: School of Biosciences 2, University of Melbourne, Parkville, Vic, 3010, Australia.
authors.forename: John A
authors.initials: JA
authors.lastname: West
authors.affiliation: Kobe University Research Center for Inland Seas, Rokkodai, Nadaku, Kobe, 657-8501, Japan.
authors.forename: Takeaki
authors.initials: T
authors.lastname: Hanyuda
authors.affiliation: School of Biosciences 2, University of Melbourne, Parkville, Vic, 3010, Australia.
authors.forename: Adele
authors.initials: A
authors.lastname: Neale
authors.affiliation: Lake Akan Eco-Museum Center, Akano-onsen 1-1-1, Akan, Hokkaido, 085-0467, Japan.
authors.forename: Isamu
authors.initials: I
authors.lastname: Wakana
authors.affiliation: Botany Department, Auckland Museum, Private Bag 92018, Auckland, 1142, New Zealand.
authors.forename: Mike D
authors.initials: MD
authors.lastname: Wilcox
authors.affiliation: Institute of Biological Sciences, Applied Ecology & Phycology, University of Rostock, D-18059, Rostock, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Karsten
authors.affiliation: School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand.
authors.forename: Giuseppe C
authors.initials: GC
authors.lastname: Zuccarello
mesh_terms: D000460:Chlorophyta / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics*; D048028:DNA, Algal / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D017753:Ecosystem; D010802:Phylogeny; D054712:Salinity; D017422:Sequence Analysis, DNA
chemical_list: D048028:DNA, Algal; D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer
keywords: 
  Cladophorella
  ; 
  rDNA
  ; Ulvophyceae; green algae; karyology; molecular phylogenetics; polyploidy; sexual reproduction; taxonomy