• ALGAE
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• v.22 no.3
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• pp.147-152
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• 2007

We described two brownish freshwater Cryptomonas species, C. marssonii Skuja and C. pyrenoidifera Geitler as first records in Korea. The identification was based on light microscopy, scanning electron microscopy, and nuclear SSU rDNA sequences analysis. Cryptomonas marssonii is characterized by its sigmoid shape with a sharply pointed and dorsally curved antapex, dorso-ventrally flattened cell, two lateral plastids without pyrenoid, and its dimension of 18-25 μm in length and 8-13 μm in width. Cryptomonas pyrenoidifera is characterized by ovoid to elliptical shape with a partially twisted or rounded antapex, dorso-ventrally biconvex cell, lateral plastids with two pyrenoids, and the dimensions of 15-22 μm in length and 10-14 μm in width. Nuclear SSU rDNA sequences between C. marssonii WCK01 from Korea and CCAC0086 from Gernmay, and between C. pyrenoidifera WCK02 from Korea and CCMP152 from Australia were identical, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.73-78
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• 2008

Water resource can be examined using biological sensors. Algae has been one of the biological sensors used to evaluate and to monitor the water pollution. The monitoring system, however, has not been used to determine what kind of the toxicological substance is in the water. It needs additional expensive chemical test to figure out the cause of the water pollution. In this study, an endeavor is made to identify the toxicant in the water using the shape of the chlorophyll fluorescence induction curve(FIC) from algae using monitoring system. Fundamental curves are obtained from the experiments with specified amount of toxicant. Baysian method is utilized to determine the unknown toxicant in the water by comparing it with the fundamental curves. The results shows that the proposed method works fairly well.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3122-3127
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• 2007

Water resource can be examined using biological sensors. Algae has been one of the biological sensors used to evaluate and monitor the water pollution. The monitoring system, however, could determine whether the examined water was safe or not. It needs additional expensive chemical test to figure out the cause of the water pollution. In this study, an endeavor is given to identify the toxicant in the water using the shape of the chlorophyll fluorescence induction curve(FIC) from algae using monitoring system. Fundamental curves are obtained from the experiments with specified amount of toxicant. Baysian method is utilized to determine the unknown toxicant in the water by comparing it with the fundamental curves. The results shows that the proposed method works fairly well.

• ALGAE
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• v.27 no.4
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• pp.235-247
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• 2012

Regardless of continuous researches, recent researches on the genus Eucampia (Bacillariophyceae) have focused mainly on E. zodiacus f. zodiacus In the present study, species of the genus Eucampia have been studied based on their morphological characteristics. Eucampia species were collected at 24 sites from July 2008 to June 2011 in Korean coastal waters. Species were mainly identified based on the shape of valve, ocellus, and aperture, along with the length and shape of the bipolar elevations. As a result, five Eucampia species were identified: Eucampia cornuta, E. groenlandica, E. zodiacus f. zodiacus, E. zodiacus f. cylindrocornis, and E. zodiacus var. cornigera. E. cornuta and E. groenlandica have long pervalvar axis length, but the others display short or moderate length. Ocellus shape of E. cornuta, E. groenlandica and E. zodiacus f. cylindrocornis are linear ribs, whereas E. zodiacus f. zodiacus and E. zodiacus var. cornigera have radial ribs with central area. E. cornuta and E. zodiacus f. cylindrocornis have long and narrow cylindrical elevations. E. groenlandica and E. zodiacus f. zodiacus have short and broad elevations with blunt tips. E. zodiacus var. cornigera has long and broad conical elevations. In terms of aperture shape, E. cornuta has large elliptical form, E. groenlandica has almost circular to rounded rectangular form, E. zodiacus f. zodiacus has narrow and elliptical rounded rectangular to a narrow lanceolate form, E. zodiacus f. cylindrocornis has almost rectangular form, and E. zodiacus var. cornigera has rounded rhombic form. On the basis of elevations in broad girdle view, 5 Eucampia taxa could be divided into 3 types: 'narrow H type', E. cornuta and E. groenlandica; 'regular H type', E. zodiacus f. cylindrocornis and E. zodiacus var. cornigera (partial); 'wide H type', E. zodiacus f. zodiacus (almost).

• ALGAE
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• v.18 no.4
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• pp.239-253
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• 2003

The morphotaxonomic characters of the genus Spirogyra were investigated to clarify their taxonomic category and the variation range among species on the basis of comparative morphological and numerical analyses by unialgal cultures and field samples collected from various freshwater habitats in Korea. 25 characters selected on morphological feature of the species were examined on 568 individuals for morphological comparisons and numerical analyses. Width, length and their length/width ratio of vegetative cell, shape of septum, chloroplast number, maximum width, width, length and their length/width ratio of female gametangium, length of male gametangium, size and shape of zygospore, and cell wall ornamentation of the spore showed a comparatively high vector in principal component analysis. In cluster analysis, 15 taxa analysed were divided into 8 major groups by the average taxonomic distance 1.0 level. Considering the morphology and numerical analysis, Spirogyra crassoidea could not be recognized as an independent species, therefore it was treated as a variety of S. ellipsospora. S. koreana (nom. invalidum), recognized as a new taxon, is under the investigation for its clear taxonomic category.

• ALGAE
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• v.27 no.4
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• pp.225-234
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• 2012

Zygnema is a conjugating filamentous green algal genus that is distributed in a broad range of freshwater habitats, from sea level to alpine summits. Although more than 150 species have been described worldwide, their taxonomy remains unclear, probably owing to their relatively simple morphology. We investigated the detailed morphology of Korean Zygnema species, combined with analysis of the plastid psbA gene from 22 specimens of the genus and putative relatives, in order to develope a key to their identification and isolation, and to determine their relationships. We recognized two species of Zygnema; Z. insigne and Z. leiospermum, based on morphological characters such as width of the vegetative cell, position of zygospores, dimensions and form of spores, shape of female gametangia, and color of mesospores. The analysis of psbA data was consistent with morphological comparison. The pairwise divergence between two species was 3.7-4.1% (34-38 bp) in psbA sequences. The phylogeny of psbA revealed the monophyly of Z. insigne and Z. leiospermum together with two isolates of Z. circumcarinatum from Germany and Scotland. This is the first report on the psbA gene phylogeny of Zygnema.

• ALGAE
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• v.35 no.4
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• pp.325-335
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• 2020

A new diatom species, Mayamaea vietnamica sp. nov., is described from Cát Tiên National Park in Vietnam. This species was discovered and described from soil samples. Algae from soil ecosystems in Vietnam are almost unknown. The new species is described on the basis of an integrated approach with molecular and morphological data, and comparison with similar species. In terms of molecular data, 18S rDNA (including V4 domain), and partial rbcL plastid genes show M. vietnamica sp. nov. is most closely related to M. terrestris N. Abarca and R. Jahn, and together they form a monophyletic group relative to other members of the genus. M. vietnamica sp. nov. differs from other species in the genus by the number of striae and areolae in 10 ㎛, number of areolae per stria, as well as shape and presence or absence of axial and central areas.

• ALGAE
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• v.21 no.4
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• pp.407-416
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• 2006

Low molecular weight carbohydrates, phycobilin pigments and cell structure using light and transmission electron microscopy were used to describe a new genus of unicellular red algae, Erythrolobus coxiae (Porphyridiales, Porphyrideophyceae, Rhodophyta). The nucleus of Erythrolobus is located at the cell periphery and the pyrenoid, enclosed by a cytoplasmic starch sheath, is in the cell center. The pyrenoid matrix contains branched tubular thylakoids and four or more chloroplast lobes extend from the pyrenoid along the cell periphery. A peripheral encircling thylakoid is absent. The Golgi apparatus faces outward at the cell periphery and is always associated with a mitochondrion. Porphyridium and Flintiella, the other members of the Porphyrideophyceae, also lack a peripheral encircling thylakoid and have an ER-mitochondria-Golgi association. The low molecular weight carbohydrates digeneaside and floridoside are present, unlike both Porphyridium and Flintiella, which have only floridoside. The phycobilin pigments B-phycoerythrin, R-phycocyanin and allophycocyanin are present, similar to Porphyridium purpureum. The cells have a slow gliding motility without changing shape and do not require substrate contact. The ultrastructural features are unique to members of the Porphyrideophyceae and recent molecular analyses clearly establish the validity of this new red algal class and the genus Erythrolobus.

• ALGAE
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• v.26 no.4
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• pp.317-325
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• 2011

Five benthic species of the genus Gambierdiscus (Dinophyceae) were observed for the first time in the coastal waters of Pakistan, Northern Indian Ocean. The morphology of the epiphytic, ciguatera-related toxic species G. toxicus, G. belizeanus, G. polynesiensis, G. australes and G. cf. yasumotoi are presented here, described by the Kofoid system of thecal plates Po, 3', 7", 6c, 8s, 5"', 1p, 2"" with differences in cell shape, cell size, plates, pores around the apical pore plate by using light and scanning electron microscopy. The occurrence of these potentially toxic dinoflagellate species in Pakistani coastal areas of Manora Channel and Balochistan during high temperatures of 28-$32^{\circ}C$ is cause of concern for human health impacts from ciguatera fish poisoning.

• ALGAE
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• v.20 no.2
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• pp.77-90
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• 2005

Eight species of Sargassum subgenus Bactrophycus section Teretia were collected from the coasts of Korea: S. confusum C. Agardh, S. pallidum (Turner) C. Agardh, S. muticum (Yendo) Fensholt, S. thunbergii (Mertens ex Roth) Kuntze, S. fulvellum (Turner) C. Agardh, S. hemiphyllum (Turner) C. Agardh, S. nipponicum Yendo, and S. miyabei Yendo. These species were investigated on morphological variations and geographical distribution in Korea. The valuable taxonomic characters between similar species of this section were discussed with special reference to thickness of leaves, types of holdfasts, shape of leaves and vesicle, and length of rhizoids.