Species diversity of the genus Thalassiosira (Thalassiosirales, Bacillariophyta) in South Korea and its biogeographical distribution in the world

Abstract:

Thalassiosira species are an important component of phytoplankton populations, and most species are considered cosmopolitan. Many authors have investigated the diversity of Thalassiosira species in order to understand their ecological roles in local areas. Our regional taxonomic study revealed the presence of 44 Thalassiosira species at 124 sites in Korean coastal waters. Of these, 14 species are newly reported in Korean waters and are described in detail with external and internal valve illustrations. Some morphologically confused taxa, such as the Thalassiosira s.s. group, T. curviseriata/T. tealata, T. simonsenii/Planktoniella blanda and T. proschkinae/T. spinulata, are clearly distinguished using additional morphological criteria. In addition, the full biogeographical distribution of Thalassiosira is described and compared with the Korean species. Korean waters seem to be the ‘Maginot Line’ for the cold- and warm-water Thalassiosira species. Knowledge of Thalassiosira species diversity will increase with more intensive work in relatively little-studied regions, such as the Indo-Pacific and tropical Atlantic Oceans.

Key Words::

• Biogeography
• Diatoms
• Phytoplankton
• Thalassiosira

ACKNOWLEDGEMENTS

We thank two anonymous reviewers, Dr. J.P. Kociolek and Dr. E.C. Theriot for the constructive comments, and Dr. D.J. Garbary for editing the manuscript with constructive comments. The fixed phytoplankton samples including Thalassiosira rosulata were provided from the Library of Maine Samples, Korea Institute of Ocean Sciences & Technology, South Korea. This work was supported by a grant from the National Institute of Biological Resources (NIBR No. 201501204) and by the Ministry of Environment of the Republic of Korea (#416-111-008, Development of biosensor technology using microalgal resources of The Eco-Innovation Project in 2015).

SUPPLEMENTARY DATA

Supplementary data associated with this article can be found online at http://dx.doi.org/10.2216/15-66.1.s1