A new non-toxic species in the dinoflagellate genusAzadinium:A. poporumsp. nov.

Abstract

A new dinoflagellate species, Azadinium poporum sp. nov., was isolated as three clones from the southern North Sea off the Danish coast. In contrast to the type species A. spinosum, a known producer of azaspiracid (AZA) toxins, the isolates of A. poporum produce no known AZA analogues detectable by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Azadinium poporum is a small (11-16 mm length; 8-12 mm width) photosynthetic dinoflagellate with a thin theca exhibiting the Kofoidean plate tabulation: Po, cp, X, 4 0 , 3a, 6 00 . 6C, 5?S, 6 000 , 2 0000 . This species is morphologically distinguished from the type A. spinosum by a slightly lower mean cell length/width ratio, consistent absence of an antapical spine, the presence of more than one stalked pyrenoid, and the conspicuous arrangement of the ventral pore, located at the junction of the pore plate and the first two apical plates. This latter feature also distinguishes A. poporum from A. obesum. As in A. spinosum, but differing from A. obesum, the first precingular (1 00 ) plate of A. poporum touches the first epithecal intercalary plate 1a. DNA sequences and phylogenetic analysis of four nuclear-encoded genes, namely the internal transcribed spacer (ITS), 18S rDNA, 28S rDNA (D1/D2) and cytochrome oxidase I (COI), support the separation of A. poporum from (but with a close affinity to) other Azadinium species (A. obesum and A. spinosum), as well as its description as a distinct species within the recently erected genus Azadinium Elbra¨chter & Tillmann. Nevertheless, in spite of the phylogenetic consistency at the generic level, the position of the genus with respect to higher taxonomic levels within the subclass Peridiniphycidae could not be further clarified.

Morphology, molecular phylogeny and azaspiracid profile of Azadinium poporum (Dinophyceae) from the Gulf of Mexico

“…The cysts might be too small, too inconspicuous and rare, thus escaping microscopic detection during routine plankton surveys and cyst studies so far. In line with previously observations Tillmann et al, 2011), the Gulf of Mexico strain A. poporum cells also sometimes show aberrant plate patterns in culture.…”

Growth and bioactive secondary metabolites of arctic Protoceratium reticulatum (Dinophyceae)

“…Additionally, the plate pattern was analyzed using an electron microscope (FEI Quanta FEG 200, Eindhoven, The Netherlands). Therefore, a sample of isolate PR3 from an exponentially growing culture was fixed with Lugol (1% final concentration), collected on a polycarbonate filter (5 mm pore size, Millipore), dehydrated, mounted on stubs, and sputter-coated as described in Tillmann et al (2010Tillmann et al ( , 2011.…”

Feeding by heterotrophic protists and copepods on the photosynthetic dinoflagellate Azadinium cf. poporum from western Korean waters

“…The production of AZAs was previously associated with a small photosynthetic dinoflagellate ), designated as Azadinium spinosum Elbrächter et Tillmann and assigned to a new genus ). The genus Azadinium is now composed of 4 well defined species, namely A. spinosum Elb räch ter et Tillmann ), A. obesum Tillmann et Elbrächter (Tillmann et al 2010), A. poporum Tillmann et Elbrächter (Tillmann et al 2011), and A. caudatum (Halldal) Nézan et Chomérat (Nézan et al 2012). Undefined species were also described as A. cf.…”