Morphological variation, ultrastructure, pigment composition and phylogeny of the star-shaped dinoflagellateAsterodinium gracile(Kareniaceae, Dinophyceae)

The Harmful Unarmored Dinoflagellate Karlodinium in Japan and Philippines, with Reference to Ultrastructure and Micropredation of Karlodinium azanzae sp. nov. (Kareniaceae, Dinophyceae)1

“…Species of Karlodinium have a wide geographic distribution as they are not only found in tropical and temperate regions but also in cold subpolar waters (e.g., K. antarcticum and K. corrugatum ; de Salas et al 2008). To date, K. veneficum has been the most widely reported Karlodinium species based on DNA sequences (Table in the Supporting Information), that is, Australasia (Australia, New Caledonia, and New Zealand), Asia (China, Japan, and Qatar), Europe (England, France, Germany, Italy, and Norway), and USA (Guillou et al 2002, Bergholtz et al 2005, Siano et al 2009, Wang et al 2011, Nézan et al 2014, Al Muftah et al 2016, Kawachi et al 2016, Luo et al 2018, Benico et al 2019a). Other species found both in Japan and Philippines are likely to be distributed at least in the Asian Pacific waters (i.e., K. australe , K. ballantinum , K. decipiens , and K. zhouanum ; de Salas et al 2005a, 2008, Tan et al 2013, Lim et al 2014, Luo et al 2018).…”

“…TEM specimens of Karlodinium azanzae (GBMG68 strain) were prepared according to Benico et al (2019a), in which the fixation time was slightly modified from the protocol described by Iwataki et al (2010). Briefly, cells were pre‐fixed in 2% (v/v) glutaraldehyde for 1 h, and post‐fixed in 1% (w/v) OsO 4 for 8 h, followed by dehydration through an ethanol series.…”

“…Approximately 50 mL of exponentially growing cultures of Karlodinium azanzae and K. australe was prepared for the HPLC analysis, and analyzed as described in Benico et al (2019a). Peaks of chlorophylls and carotenoids were identified by referring their retention times and absorption spectra from certified pigment standards (Danish Hydraulic Institute, Hørsholm, Denmark).…”

“…Several thermal conditions for PCR were applied, and the most successful condition was as follows: an initial denaturation step at 98ºC for 6 min, followed by 35 cycles of three steps, 95ºC for 10 s, 50ºC for 10 s, and 72ºC for 3 min, and finally an elongation step of 72ºC for 6 min. Amplicons were purified using a QIAquick PCR Purification Kit (Qiagen Genomics, Bothell, WA, USA) after the confirmation by 1.0% agarose gel electrophoresis, and DNA sequencing was performed as described in Benico et al (2019a). DNA sequences of ITS and partial LSU rDNA determined from the seven Karlodinium species were deposited in GenBank (Table 1).…”

“…Species composition of Karlodinium has not been fully understood in Japanese and Philippine coastal waters. To date, K. veneficum is the only Karlodinium species with DNA sequences reported from Japan (Kawachi et al 2016, Benico et al 2019a), although several small unarmored dinoflagellates similar to Karlodinium were earlier reported based on their morphology (e.g., Hada 1976, Throndsen 1983, Takayama 1998). In the Philippines, there was no record of Karlodinium occurring.…”