• ALGAE
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• v.23 no.3
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• pp.187-199
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• 2008

A study on the fine structure of the marine diatom Thalassiosira has been carried out during the periods from January 2007 to March 2008 in Korean coastal waters. As the third series of the Thalassiosira species, a fine structure, description, distribution and taxonomic remarks of the six Thalassiosira species were observed by means of light microscope and scanning electron microscope. The critical features of Thalassiosira species were a shape of external tubes of marginal strutted processes and labiate process. Six species showed each different shape of external tubes, marginal strutted processes and labiate process. The shape of external tube was divided into five types: T shape of Thalassiosira curviseriata, small-rounded shape of T. lundiana, double-layer form and flame shape of T. nordenskioeldii, tulip shape of T. punctigera and tooth-shape of T. tenera. This external character may be able to key character for positive identification of the Thalassiosira species. Of these Thalassiosira lundiana, T. minuscula and T. tenera were new records for Korean coastal waters.

• ALGAE
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• v.25 no.3
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• pp.121-131
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• 2010

Thalassiosira species were collected from October 2007 to January 2009 in an attempt to better understand species diversity of the genus Thalassiosira in Korean coastal waters. A total of 5 Thalassiosira species (T. concaviuscula, T. oceanica, T. partheneia, T. simonsenii and T. nanolineata) were identified here. Most species in this study were of small size, and 5 species were recorded for the first time in Korean coastal waters. Using a scanning electron microscope (SEM), we described distinctive characteristics of fine structure that proved to be important diagnostic characteristics for the identification of each species. The most important diagnostic characteristics for Thalassiosira species identification were the marginal strutted processes, the position of labiate processes, and the areolation. The differential characteristics of the species studied were: T. concaviuscula has a double layered external tubes on the marginal strutted processes; T. oceanica shows marginal ridges that are interlinked between the marginal strutted processes; the valve face of T. partheneia is fairly convex and its labiate process is positioned midway between two strutted processes; T. simonsenii is characterized by two labiate processes and somewhat coarse areolae; and, T. nanolineata has several central strutted processes and linear areolation.

• ALGAE
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• v.22 no.4
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• pp.253-259
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• 2007

This study deals with the taxonomy of the marine diatom Ditylum brightwellii (West) Grunow: shape, size and ratio, marginal ridge, labiate process, areolation, and seasonal distribution are all considered. Ditylum brightwellii were divided into two type; prism- and cylinder-shaped. Comparisons between specimens from the Yellow Sea were made on, (1) shape- prism types are prismatic-shaped and/or regular square or right-angled tetragon, cylinder types are cylinder-shaped and/or long right-angled tetragon in the girdle view, respectively; (2) size and ratiodiameters of prism types are 82.1 ± 2 μm, while those of cylinder types are 21.2 ± 5 μm and ratio of pervalvar axis/diameter- prism types cells are 1.0-1.5, but cylinder types are 3.9-5.5; (3) marginal ridges- prism types have dotted, while those of the cylinder-type cells have piece, slotted or fimbriated on the marginal ridge; (4) labiate process- both prism- and cylinder-types are central part in valve face, but length of labiate processes of prism types are longer than those of cylinder types; (5) cell margin- the girdle margin show many shallow furrows in prism type and smooth in cylinder type; (6) areolation- both prism- and cylinder-types are a radial pattern in the valve center, but areolae of prism types are larger than those of cylinder types; (7) seasonal distribution- cylinder types are dominated in summer and prism types in the other seasons.

• 한국해양학회지
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• v.22 no.3
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• pp.179-190
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• 1987

A study on the fine structure of the marine diatoms has been carried out for taxonomical purpose during the periods from September 1983 to March 1987 in Korean coastal waters. Fine structure of smallThalassiosira(Bacillariophyceae) was studied by means of light microscope and scanning electron nisroscopy. Secondarily, six species of Thalassiosira were identified and described. Of these Thalassiosia allenii, T. binata and T. conferta were new records for Korean coastal waters. Thalassiosira aestivalis, T.allenii, T.binata, T.conferta, and T. pacifica have a valve with a single labiate process and one central and one marginal ring of strutted processes, but T.rotula has many central strutted processes close together instead of one central strutted process.

• ALGAE
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• v.24 no.2
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• pp.67-77
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• 2009

The marine phytoplankton diatom Thalassiosira species are described from the Korean coastal waters, based onobservations of Fine structutre of its frustules. As a fourth series, this study deals with 5 Thlassiosira species (T. decip-iens, T. ecgentrica, T. mala, T. nodulolinmta, and T. proschinae). The most striking features of these species are also theform and position of two processes on frustules. There is a central strutted process on valve face except T. nodvlolin-eata, which has a modified one on its center. The extemal tubes of marginal strutted processes are divided twoforms: "pile" form in T. decipiens and T. proschkinae, "short straw" form in T. eccentrica and T. nodulolineata. T. maladoes not present the extemal tubes in valve margin. The labiate processes are located in valve margin except T.proschkinae, which has it on valve face. Of theae, thrce species (T. mala, T. nodulineata at a final contentration of 5%and T. proschkinae were newly recorded in the coastal waters of Korea.

• ALGAE
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• v.21 no.2
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• pp.169-174
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• 2006

We have cultured more than 100 Arctic and Antarctic cryophilic microalgal strains in KOPRI culture collections of polar microorganisms (KCCPM). Among them, we tried to identify an Antarctic strain, KOPRI AnM0008 by morphological and molecular analysis. Nuclear SSU rDNA and plastid rbcL sequences were used to identify the strain. It was identified as Porosira pseudodenticulata based on SSU sequence data showing 99% identity with GenBank X85398. This result was supported by morphological features like solitary labiate process, external foramina and internal cribra by optical and scanning electron microscope. Morphological identification and molecular analysis on polar cryophilic microalgae will be accomplished to construct the databases for KCCPM.