Does the seagrass Posidonia really occur in Madagascar?

摘要: In a recent (March) issue of Phycologia (47: 203–212), West et al. (2008) described new species Rhodophyta, Rhodachlya madagascarensis J.A. West, J.L. Scott, K.A. U. Karsten, S.L. Clayden & G.W. Saunders, that also constituted genus, family and order. According to (2008), is small epiphyte growing on ‘Posidonia blades’ near Ifaty, Madagascar (Indian Ocean) (Abstract: p. 203; Material methods, 204; Latin diagnosis, 205 Acknowledgements, 210). Although they do not mention the authorship Posidonia, it clear are referring plant Posidonia Konig in Sims (1805), mollusc Bronn 1828, legitimate name genus bivalves under International Code Zoological Nomenclature, widespread Carboniferous (e.g. Amler Winkler Prins 1999). (Magnoliophyta, Posidoniaceae) seagrasses with clearcut antitropical pattern distribution, which encompasses nine species: oceanica (Linnaeus) Delile, endemic Mediterranean Sea, eight Australia: P. angustifolia Cambridge Kuo, australis J.D. Hooker, coriacea denhartogii Kuo Cambridge, kirkmanii ostenfeldii den Hartog, robertsoniae sinuosa (Hartog 1970; 1990; Hartog 2001; 2006). Campey (2000) Spalding (2003), may be synonym coriacea. The Australian all found Western Australia. angustifolia, coriacea, additionally South Australia, occurs New Wales, Tasmania, Victoria Australia (van Keulen 2008). All these probably descended from Tethyan fossil cretacea Hosius von der Mark, and/or perforata de Saporta Marion parisiensis (Brongniart) Fritel (Larkum 1989; restricted Sea 2006), some overseas records can literature. them have proved erroneous. earliest most amusing specific species; Linnaeus, who first named (as Zostera oceanica), inverted two parcels received Atlantic Ocean, respectively, therefore ‘oceanica’ (i.e. Ocean). Further Bay Biscay (Atlantic, France) Sauvageau 1890) actually concern large-leaved forms marina Linnaeus. More surprising was inclusion within Texas (Gulf Mexico, USA) flora by Correll Johnston (1970: 95), subsequently illustrated (1972: 129– 130) their authoritative aquatic wetland plants southwestern United States [as oceania (sic)]. McMillan (1975) established gross misidentification, specimens fact belonging Thalassia testudinum Banks ex Sims. Finally, oceanica, Red northern Indian Ocean Makkaveeva 1968) should refer hemprichii (Ehrenberg) Ascherson Petermann, seagrass widely distributed throughout including Madagascar, often associated mangrove habitats 1970). present day knowledge, temperate seas. occurrence this mangroves around intertropical zone, is, therefore, highly unlikely, though impossible. If record confirmed, would constitute disjointed distributional for genus. We suspect, based morphological similarities, host more likely or Enhalus acoroides Hydrocharitaceae (see 2003).