Taxonomic clarification of the dinophyte Rhabdosphaera erinaceus Kamptner, ≡ Scrippsiella erinaceus comb. nov. (Thoracosphaeraceae, Peridiniales)

Abstract

The Scrippsiella trochoidea species complex (Thoracosphaeraceae, Peridiniales) consists of a cryptic diversity and multiple species, for which established scientific names are not available at present. Previously, the name Scrippsiella trochoidea has been taxonomically clarified, leaving a reliable determination of morphologically similar, but only distantly related species impossible. We isolated and cultivated Scrippsiella erinaceus comb. nov. (strains GeoM*533 and GeoM*534) from material collected near the type locality off Rovinj, Republic of Croatia (Adriatic Sea). We barcoded the species of the Thoracosphaeraceae using rRNA sequences (including 22 new sequences) and investigated the morphology of the strains using light and electron microscopy. The Scrippsiella trochoidea species complex was composed of three primary clades, and the Adriatic strains were reliably assigned to one of them being distinct from the true Scrippsiella trochoidea. We designate an epitype for the basionym Rhabdosphaera erinaceus prepared from the strain GeoM*534. The unambiguous links between a scientific species name, its protologue, genetic characterization and spatial distribution have particular importance for character-poor, unicellular organisms such as the Dinophyceae.

Key words:

• calcareous dinoflagellates
• coccoid cell
• cryptic species
• distribution
• epitypification
• morphology
• phylogeny
• Rhabdothorax
• theca

Acknowledgements

We thank Juliane Vehof (Berlin) for providing us with the sediment sample as well as Kenneth Karol (New York), Fred Rögl and Anton Igersheim (both Vienna) for information about original material of E. Kamptner and J. Schiller. Eva Facher, Martina Silber and Sylvia Söhner (all Munich) supported our lab work, which is gratefully acknowledged here. We are grateful to two anonymous reviewers who provided useful comments on our study.

Associate Editor: Elliot Shubert

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Funding

Financial support was provided by the Deutsche Forschungsgemeinschaft [grants KE 322/36, RI 1738/5 and WI 725/25] and the Münchener Universitätsgesellschaft.