Platychrysis moestrupii sp. nov. (Prymnesiophyceae): a new dimorphic, sand-dwelling haptophyte species from southeastern Australia

Abstract

Grant B., Waller R.F. and Wetherbee R. 2011. Platychrysis moestrupii sp. nov. (Prymnesiophyceae): a new dimorphic, sand-dwelling haptophyte species from southeastern Australia. Phycologia 50: 608–615. DOI: 10.2216/11-14.1A marine prymnesiophyte, Platychrysis moestrupii sp. nov., is described. Clonal cultures were established from field samples collected during the summer of 2009 from Stewart's Bay, Tasmania, Australia. Cells of P. moestrupii have two distinct morphologies, a motile swimming phase and an adhesive benthic phase. Motile cells are oblong to cylindrical with a posterior rounded protuberance and are 50–65 µm long and 20–25 µm wide. The cells possess two equal to subequal homodynamic flagella and a flexible noncoiling haptonema (8–10 µm long). Benthic cells are irregularly discoid with a diameter of 50–65 µm and are adherent to the substrate. Cells possess scales of two types, both of which are elliptical and 300 by 500 nm. Distal scales are unique amongst Platychrysis and have a marginal series of hair-like spines, a loculate peripheral margin and an internal structure that appears aveolate. Phylogenetic analysis based on the nuclear encoded SSU ribosomal sequence places P. moestrupii with other Platychrysis taxa, although the internal topology of this clade is poorly resolved.