TAKAYAMA GEN. NOV. (GYMNODINIALES, DINOPHYCEAE), A NEW GENUS OF UNARMORED DINOFLAGELLATES WITH SIGMOID APICAL GROOVES, INCLUDING THE DESCRIPTION OF TWO NEW SPECIES¹

Abstract

A new potentially ichthyotoxic dinoflagellate genus, Takayama de Salas, Bolch, Botes et Hallegraeff gen. nov., is described with two new species isolated from Tasmanian (Australia) and South African coastal waters: T. tasmanica de Salas, Bolch et Hallegraeff, sp. nov. and T. helix, de Salas, Bolch, Botes et Hallegraeff, sp. nov. The genus and two species are characterized by LM and EM of field samples and laboratory cultures as well as large subunit rDNA sequences and HPLC pigment analyses of several cultured strains. The new Takayama species have sigmoid apical grooves and contain fucoxanthin and its derivatives as the main accessory pigments. Takayama tasmanica is similar to the previously described species Gymnodinium pulchellum Larsen, Gyrodinium acrotrochum Larsen, and G. cladochroma Larsen in its external morphology but differs from these in having two ventral pores, a large horseshoe‐shaped nucleus, and a central pyrenoid with radiating chloroplasts that pass through the nucleus. It contains gyroxanthin‐diester and a gyroxanthin‐like accessory pigment, both of which are missing in T. helix. Takayama helix has an apical groove that is nearly straight while still being clearly inflected. A ventral pore or slit is present. It has numerous peripheral, strap shaped, and spiraling chloroplasts with individual pyrenoids and a solid ellipsoidal nucleus. The genus Takayama has close affinities to the genera Karenia and Karlodinium.

Development of a Dinoflagellate-Oriented PCR Primer Set Leads to Detection of Picoplanktonic Dinoflagellates from Long Island Sound

“…The ease with which novel lineages were isolated also suggests that dinoflagellate diversity has been underestimated. However, this observation should not be surprising given that even in the larger cell size range new species have frequently been discovered (e.g., Stoeckeria, Takayama, Polarella, and Pfiesteria [2,3,10,14]). The dearth of information regarding the lineages of small dinoflagellates is a result of a lack of targeted analyses.…”

“…However, our knowledge of the species diversity of these organisms remains limited even though novel living (2,3,10,14) and fossil lineages (4, 19) have been discovered. Knowledge of the diversity of "small" dinoflagellates is particularly deficient.…”

Pigment-based chloroplast types in dinoflagellates

“…However, the 2 Takayama species differ in that the occurrence of GyrE is restricted to T. tasmanica, and Hex-fuco is only detected in T. cf. helix (de Salas et al 2003). The other 4 Takayama species have not yet been analysed for pigment composition: T. acrotrocha, T.…”

“…Information on chloroplast pigments has usually been reported in new descriptions of dinoflagellates (e.g. Fraga et al 1995, Elbrächter & Schnepf 1996, Bolch et al 1999, Daugbjerg et al 2000, Montresor et al 2003, de Salas et al 2003, 2004, 2005, Garcés et al 2006, Tillmann et al 2009, Sampedro et al 2011.…”

Ecology of Gymnodinium aureolum. I. Feeding in western Korean waters

“…However, it is difficult to determine whether Gyrodinium aureolum isolates reported by researchers before Hansen et al (2000) and Daugbjerg et al (2000) were Gymnodinium aureolum or K. mikimotoi. An increasing number of taxonomic studies have been conducted on Gymnodinium aureolum strains isolated after the year 2000 (de Salas et al 2003, Bergholtz et al 2006, Tang et al 2008.…”