title: Molecular phylogeny of Zeacarpa (Ralfsiales, Phaeophyceae) proposing a new family Zeacarpaceae and its transfer to Nemodermatales.
abstract: Zeacarpa leiomorpha is a crustose brown alga endemic to South Africa. The species has been tentatively placed in Ralfsiaceae, but its ordinal assignment has been uncertain. The molecular phylogeny of brown algae based on concatenated DNA sequences of seven chloroplast and mitochondrial gene sequences (atpB, psaA, psaB, psbA, psbC, rbcL, and cox1) of taxa covering most of the orders revealed the most related phylogenetic relationship of Z. leiomorpha to Nemoderma tingitanum (Nemodermatales) rather than Ralfsiaceae (Ralfsiales). Morphologically, Zeacarpa and Nemoderma share crustose thallus structure and multiple discoidal chloroplasts without pyrenoids in each cell, however, the formation of lateral unilocular zoidangia in tufts in loose upright filaments in Zeacarpa is distinctive in brown algae. Considering the relatively distant genetic divergence between the two taxa, comparable to that among families or orders in representative brown algae, in addition to the above-mentioned unique morphological features, we propose the classification of Zeacarpa in a new family Zeacarpaceae in the order Nemodermatales.
authors.affiliation: Kobe University Research Center for Inland Seas, 1-1 Rokkodai, Kobe, 657-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawai
authors.affiliation: Kobe University Research Center for Inland Seas, 1-1 Rokkodai, Kobe, 657-8501, Japan.
authors.forename: Takeaki
authors.initials: T
authors.lastname: Hanyuda
authors.affiliation: Department of Biological Sciences and Marine Research Institute, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa.
authors.forename: John
authors.initials: J
authors.lastname: Bolton
authors.affiliation: Department of Biological Sciences and Marine Research Institute, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa.|Department of Agriculture, Forestry and Fisheries, Private Bag X2, Roggebaai, 8012, South Africa.
authors.forename: Robert
authors.initials: R
authors.lastname: Anderson
mesh_terms: D002736:Chloroplasts / Q000235:genetics / Q000648:ultrastructure; D000459:Phaeophyceae / Q000145:classification* / Q000166:cytology*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013019:South Africa
keywords: Nemodermatales; Phaeophyceae; Zeacarpa; Zeacarpaceae fam. nov.; molecular phylogeny