Chaetoceros atlanticus var. koreanus var. nov. (Bacillariophyta) from the East Sea of Korea and closely related taxa: insight into the ultrastructure of the setae

Chaetoceros atlanticus var. koreanus, a new variety of C. atlanticus, was collected from the East Sea of Korea on 20 August 2013. Its morphological characteristics were examined from wild material, and the new variety was compared with three closely related taxa, C. atlanticus var. atlanticus, C. atlanticus var. neapolitanus and C. atlanticus var. skeleton. The new taxon belongs to the subgenus Chaetoceros, which is characterized by numerous granular chloroplasts in the setae as well as the body of the cell and a rimoportula on each valve, and to the section Atlantica, which is characterized by a long tubular external rimoportula at the centre of each valve, terminal and intercalary setae differing in length and direction, and wide hexagonal apertures. Chaetoceros atlanticus var. koreanus shares its general morphological characteristics with three closely related species, but has rows of small poroids forming a grid pattern, a tetragonal cross-section, and perpendicular costae on the setae. These features are not seen in the three most closely related taxa, but are sometimes found in other species included in the subgenus Chaetoceros. We therefore designate C. atlanticus var. koreanus as a new variety of C. atlanticus.

[1]  H. Joo,et al.  Critical criteria for identification of the genus Chaetoceros (Bacillariophyta) based on setae ultrastructure. II. Subgenus Hyalochaete , 2014 .

[2]  J. Park,et al.  Critical criteria for identification of the genus Chaetoceros (Bacillariophyta) based on setae ultrastructure. I. Subgenus Chaetoceros , 2014 .

[3]  Michael D. Guiry,et al.  AlgaeBase. World-wide electronic publication , 2013 .

[4]  Jin Hwan Lee,et al.  Morphology and taxonomy of the planktonic diatom Chaetoceros species (Bacillariophyceae) with special intercalary setae in Korean coastal waters , 2011 .

[5]  D. Sarno,et al.  Comparative molecular and morphological phylogenetic analyses of taxa in the Chaetocerotaceae (Bacillariophyta) , 2010 .

[6]  T. Orlova,et al.  Morphology and ecology of the bloom-forming diatom Chaetoceros contortus from Peter the Great Bay, Sea of Japan , 2010, Russian Journal of Marine Biology.

[7]  M. Montresor,et al.  MORPHOLOGICAL VARIABILITY AND LIFE CYCLE TRAITS OF THE TYPE SPECIES OF THE DIATOM GENUS CHAETOCEROS, C. DICHAETA 1 , 2008, Journal of phycology.

[8]  D. Hernández-Becerril,et al.  The genus Chaetoceros (Bacillariophyta) from Peter the Great Bay, Sea of Japan , 2006 .

[9]  D. Hernández-Becerril,et al.  Morphological study of the marine planktonic diatom Chaetoceros castracanei Karsten (Bacillariophyceae) from Antarctic waters, with a discussion on its possible taxonomic relationships , 2004 .

[10]  E. Theriot,et al.  Chaetoceros phuketensissp. nov. (Bacillariophyceae): a new species from the Andaman Sea , 2000 .

[11]  D. Hernández-Becerril.  Chaetoceros sumatranus, a member of Chaetoceros section Coarctati, sect. nov. (Bacillariophyceae) , 1999 .

[12]  D. Hernández-Becerril.  Morphological study of the marine planktonic diatom Chaetoceros okamurai (Chaetocerotales, Bacillariophyceae) from the Gulf of Mexico , 1998 .

[13]  D. Hernández-Becerril,et al.  Species of the Diatom Genus Chaetoceros (Bacillariophyceae) in the Plankton from the Southern Gulf of Mexico , 1998 .

[14]  G. Hasle,et al.  Chapter 2 – Marine Diatoms , 1996 .

[15]  D. Hernández-Becerril.  morphological study of Chaetoceros species (Bacillariophyta) from the plankton of the Pacific Ocean of Mexico , 1996 .

[16]  C. Tomas.  Identifying marine diatoms and dinoflagellates , 1996 .

[17]  J. Pickett-Heaps,et al.  Valve and seta (spine) morphogenesis in the centric diatom Chaetoceros peruvianus Brightwell , 1994 .

[18]  D. Hernández-Becerril,et al.  OBSERVATIONS ON CHAETOCEROS BUCEROS (BACILLARIOPHYCEAE), A RARE TROPICAL PLANKTONIC SPECIES COLLECTED FROM THE MEXICAN PACIFIC 1 , 1993 .

[19]  D. Hernández-Becerril.  Note on the morphology of two planktonic diatoms: Chaetoceros bacteriastroides and C. seychellarus, with comments on their taxonomy and distribution , 1993 .

[20]  D. Hernández-Becerril.  Observations on two closely related species, Chaetoceros tetrastichon and C. dadayi (Bacillariophyceae) , 1992 .

[21]  L. Albright,et al.  Effects of the harmful diatom Chaetoceros concavicornis on respiration of rainbow trout Oncorhynchus mykiss , 1992 .

[22]  D. Hernández-Becerril.  THE MORPHOLOGY AND TAXONOMY OF THE PLANKTONIC DIATOM CHAETOCEROS COARCTATUS LAUDER (BACILLARIOPHYCEAE) , 1991 .

[23]  D. Hernández-Becerril.  Chaetoceros bermejensis sp. nov., a New Planktonic Diatom from the Gulf of California , 1991 .

[24]  P. Hargraves,et al.  Morphology and taxonomy of Chaetoceros compressus Lauder var. Hirtisetus var. nova, with preliminary consideration of closely related taxa , 1990 .

[25]  P. Hargraves,et al.  The Chaetoceros Ehrenberg (Bacillariophyceae) Flora of Narragansett Bay, Rhode Island, U.S.A. , 1988 .

[26]  E. E. Cupp.  Marine Plankton Diatoms of the West Coast of North America , 1977 .

[27]  Grethe Rytter Hasle,et al.  Diatoms: Cleaning and Mounting for Light and Electron Microscopy , 1970 .

[28]  D. Wujek,et al.  Catalog of the Fossil and Recent Genera and Species of Diatoms and Their Synonyms , 1968 .

[29]  A. Sournia.  Diatomées planctoniques du canal de Mozambique et de l'île Maurice , 1968 .

[30]  J. W. G. Lund,et al.  An Introductory Account of the Smaller Algae of British Coastal Waters. Part V. Bacillariophyceae (Diatoms). , 1965 .

[31]  F. Hustedt,et al.  Die Kieselalgen : Deutschlands, Österreichs und der Schweiz : unter Berücksichtigung der übrigen Länder Europas sowie der angrenzenden Meeresgebiete , 1961 .

[32]  H. Okuno.  Electron-microscopical Study on Fine Structures of Diatom Frustules XVI , 1957 .

[33]  H. Okuno.  Electron-microscopical Study on Fine Structures of Diatom Frustules XIV , 1956 .

[34]  H. Gran.  Protophyta: Diatomaceæ, Silicoflagellata og Cilioflagellata , 1897 .

[35]  G. Walker-Arnott.  What are Marine Diatoms , 1859 .