Phylogeny and Synonymy of Gyrodinium heterostriatum comb. nov. (Dinophyceae), a Common Unarmored Dinoflagellate in the World Oceans

• Published in: Acta Protozoologica
• Main Authors: Gómez, Fernando, Gast, Rebecca, J, Artigas, Luis Felipe
• Other Authors: Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Nord ), Woods Hole Oceanographic Institution (WHOI), Université du Littoral Côte d'Opale (ULCO)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Dinophyta Gymnodinium new combination taxonomy molecular phylogenetics North Atlantic; Dinophyta; Gymnodinium; new combination; taxonomy; molecular phylogenetics; North Atlantic; [SDE]Environmental Sciences; [SDV]Life Sciences [q-bio]
• Online Access: https://hal.science/hal-04394551; https://hal.science/hal-04394551/document; https://hal.science/hal-04394551/file/Gomez_et-al_Acta-Protozoologica_59_2020.pdf; https://doi.org/10.4467/16890027ap.20.007.12675

International audience The North Sea and the English Channel are regions with a long tradition of plankton studies, where the colony-forming haptophyte Phaeocystis globosa dominates the spring phytoplankton blooms. Among its predators, we investigated an abundant unarmored dinoflagellate (~3000 cells per liter) in the North Sea in May 2019. It has been reported in the literature as Gymnodinium heterostriatum or G. striatissimum, and often identified as Gyrodinium spirale. Phylogenetic analyses using the small-, large subunit- and Internal Transcriber Spacers of the ribosomal RNA (SSU-, LSU-, ITS rRNA) gene sequences indicate that our isolates clustered within the Gyrodinium clade. The new sequences formed a sister group with sequences of the freshwater taxon Gyrodinium helveticum, being one of the infrequent marine-freshwater transitions in the microbial world. This isolate is the first characterized member of a clade of numerous environmental sequences widely distributed from cold to tropical seas. This common and abundant taxon has received several names due to its morphological plasticity (changes of size and shape, often deformed after engulfing prey) and the difficulty in discerning surface striation. We conclude that the priority is for the species name Gymnodinium heterostriatum Kofoid & Swezy 1921, a new name that was proposed for Gymnodinium spirale var. obtusum sensu Dogiel 1906. The species Gyrodinium striatissimum (Hulburt 1957) Gert Hansen & Moestrup 2000 and Gymnodinium lucidum D. Ballantine in Parke & Dixon 1964 (=G. hyalinum M. Lebour 1925) are posterior synonyms. We propose Gyrodinium heterostriatum comb. nov. for Gymnodinium heterostriatum.