title: Simonsenia aveniformis sp. nov. (Bacillariophyceae), molecular phylogeny and systematics of the genus, and a new type of canal raphe system.
abstract: The genus Simonsenia is reviewed and S. aveniformis described as new for science by light and electron microscopy. The new species originated from estuarine environments in southern Iberia (Atlantic coast) and was isolated into culture. In LM, Simonsenia resembles Nitzschia, with bridges (fibulae) beneath the raphe, which is marginal. It is only electron microscope (EM) examination that reveals the true structure of the raphe system, which consists of a raphe canal raised on a keel (wing), supported by rib like braces (fenestral bars) and tube-like portulae; between the portulae the keel is perforated by open windows (fenestrae). Based on the presence of portulae and a fenestrated keel, Simonsenia has been proposed to be intermediate between Bacillariaceae and Surirellaceae. However, an rbcL phylogeny revealed that Simonsenia belongs firmly in the Bacillariaceae, with which it shares a similar chloroplast arrangement, rather than in the Surirellaceae. Lack of homology between the surirelloid and simonsenioid keels is reflected in subtle differences in the morphology and ontogeny of the portulae and fenestrae. The diversity of Simonsenia has probably been underestimated, particularly in the marine environment.
authors.affiliation: Palaeoceanology Unit, Faculty of Geosciences, University of Szczecin, Mickiewicza 18, 70-383 Szczecin, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Witkowski
authors.affiliation: CIMA - Centre for Marine and Environmental Research, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Gomes
authors.affiliation: Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK.|Institute of Agriculture and Food Research and Technology (IRTA), Sant Carles de la Ràpita, Spain.
authors.forename: David G
authors.initials: DG
authors.lastname: Mann
authors.affiliation: Institute of Agriculture and Food Research and Technology (IRTA), Sant Carles de la Ràpita, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Trobajo
authors.affiliation: Palaeoceanology Unit, Faculty of Geosciences, University of Szczecin, Mickiewicza 18, 70-383 Szczecin, Poland.
authors.forename: Chunlian
authors.initials: C
authors.lastname: Li
authors.affiliation: Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia.
authors.forename: Frederik
authors.initials: F
authors.lastname: Barka
authors.affiliation: Institute of Molecular Biosciences, Goethe University, Frankfurt am Main, Germany.
authors.forename: Evgeniy
authors.initials: E
authors.lastname: Gusev
authors.affiliation: Palaeoceanology Unit, Faculty of Geosciences, University of Szczecin, Mickiewicza 18, 70-383 Szczecin, Poland.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Dąbek
authors.affiliation: Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Grzonka
authors.affiliation: Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Krzysztof J
authors.initials: KJ
authors.lastname: Kurzydłowski
authors.affiliation: Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Izabela
authors.initials: I
authors.lastname: Zgłobicka
authors.affiliation: Department of Earth and Atmospheric Sciences, 214 Bessey Hall, Lincoln, NE 68588-0340.
authors.forename: Michael
authors.initials: M
authors.lastname: Harrison
authors.affiliation: CIMA - Centre for Marine and Environmental Research, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Boski
mesh_terms: D017377:Diatoms / Q000235:genetics / Q000648:ultrastructure*; D061125:Genes, Chloroplast; D005819:Genetic Markers; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D005819:Genetic Markers