Takayama gen. nov (Gymnodiniales, Dinophyceae), a new genus of unarmored dinoflagellates with sigmoid apical grooves, including the description of two new species
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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.
History
Publication title
Journal of Phycology
Volume
39
Issue
6
Article number
6
Number
6
Pagination
1233-1246:14
ISSN
0022-3646
Department/School
Ecology and Biodiversity, IMAS Directorate, College Office - CALE
Publisher
BLACKWELL PUBLISHING INC
Publication status
Published
Rights statement
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