Four newly recorded species of the calcified marine brown macroalgal genus Padina (Dictyotales, Phaeophyceae) for Australia

Molecular phylogenetic analyses based on plastid-encoded rbcL and mitochondrial cox3 gene sequences, in combination with morphological observations, revealed the existence of the following four bistratose Padina species previouslyunreportedfromAustraliancoasts:PadinacalcareaNi-Ni-Win,S.G.A.Draisma,W.F.Prud'hommevanReine& H.Kawai, characterised by its bright yellow-orange inferior thallus surface and chalky white, heavily calcified superior surface, and the presence of hairlines only on the inferior surface; P. macrophylla Ni-Ni-Win, M.Uchimura & H.Kawai, characterised by a moderately calcified thallus with broad, depressed hairlines on the inferior surface and narrow, not depressedhairlinesonthesuperiorsurface,thosehairlinesthatarelargelyspacedoneachsurface;P.moffittianaI.A.Abbott& Huisman, characterised by lightly calcified thalli with narrow, slightly depressed hairlines that are distributed in alternate sequencebetweenthetwosurfacesatunequaldistances,andbroadreproductivesoriinoneortworowsinthefertilezone;and P.okinawaensisNi-Ni-Win,S.Arai,M.Uchimura&H.Kawai,characterisedbyheavilycalcifiedthalli,exceptatthehairlines, which form an alternation of uncalcified furrows and calcified glabrous zones on the inferior surface. With the addition of these four species, 13 Padina species are known from Australia.