title: Phylogenetic Relationships and Biogeography of the Diatom Genus Mastogloia (Bacillariophyceae): Revision of the Section Ellipticae Including the Description of New Taxa.
abstract: Benthic diatoms represent an important component of aquatic ecosystems, both for their contribution to primary production and their role in the marine food web. Mastogloia is a large, mostly marine diatom genus occurring in microphytobenthic communities of temperate to tropical coastal regions. In this study, the phylogenetic relationships, based on cladistic methodologies using morphological features, among all taxa belonging to the genus Mastogloia section Ellipticae (i.e., 33 taxa) were investigated using the parsimony method. The character states that describe variations of central area, raphe, areola vela and partectal position have a tendency to be very homologous and useful in recovering phylogenies. The typical character states of this section, such as rounded apices represents an ancestral homology. The phylogenetic hypothesis supports the probable monophyletic origin of the section Ellipticae (synapomorphy). Moreover, we completed the taxonomical review of the section Ellipticae, with the description of seven species, M. cocconeiformis, M. cribrosa, M. fimbriata, M. ovata, M. pseudolatecostata, and of two species new to science, M. rosalbae and M. aegyptiaca. Finally, this study provides historical and new information on the geographical distribution of Mastogloia species.
authors.affiliation: Department of Life and Environmental Sciences, Laboratory of Marine Botany, Polytechnic University of Marche, via Brecce Bianche, 60131 Ancona, Italy. Electronic address: c.pennesi@univpm.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pennesi
authors.affiliation: Research and Collections Division, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa, ON KIP 6P4, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Poulin
authors.affiliation: Department of Life and Environmental Sciences, Laboratory of Marine Botany, Polytechnic University of Marche, via Brecce Bianche, 60131 Ancona, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Totti
mesh_terms: D017377:Diatoms / Q000145:classification / Q000502:physiology / Q000648:ultrastructure; D017753:Ecosystem; D019143:Evolution, Molecular; D008855:Microscopy, Electron, Scanning; D010802:Phylogeny; D058974:Phylogeography
keywords: Cladistic analysis; Mastogloia; microphytobenthos; morphological features; phylogeny; section Ellipticae.