Floristic Survey of Diatom in the Three Islands (Baeknyeong, Daecheong, Socheong) from Yellow Sea of Korea

Abstract

A floristic study on the diatom was carried out in coastal area at two seasons, August 2014 and April 2015, from three islands in the northern area of Yellow Sea of South Korea. A total of 117 species of diatoms, including 3 classes, 9 subclasses, 20 orders, 32 families and 54 genera, were identified based on LM and SEM examinations. Three species of diatoms, Gyrosigma obscurum, Pleurosigma frenguellianum, and P. sabangi were newly recorded in Korea. The historical synonyms of the species are presented for the floristic informations, the examined specimen for the each taxon is specified, and the distribution in three islands and detailed sampling localities of each taxon are given.

INTRODUCTION

Diatom is a major group and most common in marine waters (Round et al.1990), and plays a major role in the primary production of marine or freshwater ecosystems (Ishii et al. 2011, Round et al. 1990). Diatoms are important in marine waters, contributing up to 45% of the primary production (Andrew and Toby 2003). In the floristic level, they are very diverse and are composed of more than 200 genera and 100,000 species worldwide (Round et al.1990, Hasle and Syvertsen 1996, Mann 1999).

Diatom flora occurring in the coastal and marine waters around Korean Peninsula were summarized to some check-lists before 1995, and the number of diatom species amounts to be 538 taxa (Lee and Cho 1985). Lee (1990) arranged a check-list of the marine fossil diatoms and Lee et al. (1995) made a check-list of 1457 diatom species from 1929 to 1993 in Korea, Lee (1995) made a checklist of 761 diatom species in Korean coastal waters. In the recent time, many authors have collected the planktonic and periphytic diatoms in the marine waters, and a number of species are newly reported with these floristic studies (Lee and Park 2008, Jung et al. 2009, Park and Lee 2010, Yun and Lee 2010, Lee and Lee 2011, Lee et al. 2012, 2013, Park et al. 2013, 2014) However, taxonomic or floristic studies of diatoms have not been reported in the three Islands (Baeknyeong, Daecheong, Socheong) in Yellow Sea of Korea, because these area adjoin the Northern Limit Line (NLL). NLL is important area in Korea, the disputed maritime boundary between North Korea and South Korea in the Yellow Sea.

Recently, the importance of biological diversity has been increasing emphasized, and the discovery of indigenous species as biological resources is recognized as an urgent national task. Due to the importance of biodiversity and bio-sovereignty in recent, check-list of indigenous species became to recognize the importance.

A master plan of “The Project on Survey and Excavation of Korean Indigenous Species” of the National Institute of Biological Resources (NIBR) under the Ministry of Environment of Korea is performing from 2006 to present. We conducted the survey and excavation of diatoms in marine and brackish waters of Korea from 2006 to the present. In consideration of these reasons, the large numbers of new record diatom species have been discovered in Korea. Lee et al. (2012) reported the newly recorded diatoms in Korea in the first conclusive study of the species, reporting 60 species in 39 genera based on light microscopy (LM) and scanning electron microscopy (SEM). Park et al. (2014) reported twenty newly recorded pennate diatoms in the marine and brackish ecosystem in Korea.

The purpose of this paper is to provide the floristic information of the diatom and add new recorded species of three diatom species in the in the Three Islands (Baeknyeong, Daecheong, Socheong) from Yellow Sea of Korea. We presented the floristic informations; basionym, synomym, reference, specimen information, occurrence of the diatom in the study area.

 

MATERIALS AND METHODS

The flora of diatom was examined at 10 stations on August 11-12, 2014 and April 22-23, 2015 from the Baeknyeong, Daecheong, and Socheong Islands in Yellow Sea of Korea (Table 1). All samples were collected using a 20-µm mesh-sized plankton nets by vertical and/or horizontal towing. Samples were immediately fixed with neutralized formalin (final concentration, 4%), glutaraldehyde (final concentration, 2%) or Lugol’s solution (Sournia 1968). To make the permanent slide and to examine the fine structures of the cells, samples were cleaned of cell organelles and organic matters with concentrated HCl and saturated KMnO4 following the Hasle and Fryxell (1970)’s modified method. Permanent slides were made with natural samples, fixed samples, and the acid-cleaned materials. The permanent slides were observed using a LM of Axioskop 40 (Carl Zeiss, Oberkochen, Germany) and Eclipse 80i (Nikon, Tokyo, Japan) with bright-field and differential interference contrast optics (Nikon) with a DS-Fil digital camera (Nikon).

Table 1.1BI, Baengnyeong Island; 2DI, Daecheong Island; 3SI, Socheong Island.

The others cleaned samples were attached to aluminum stubs and coated with gold-palladium, coated samples were examined using a JSM- 5600LV SEM (JEOL, Tokyo, Japan). Sizes of the diatom species were analyzed with Axio Vision AC ver. 4.5 image calculation software (Carl Zeiss). Diatom identifications were mainly based on Hendey (1964), Round et al. (1990), Hasle and Syvertsen (1996), and a number of references.

 

RESULTS

One hundred seventeen diatom species were identified from three islands in Korea. Of these, the three species, Gyrosigma obscurum, Pleurosigma frenguellianum, and Pleurosigma sabangi, were newly recorded in Korea. The diatom flora encountered through this survey are composed of 117 taxa, which are classified into 54 genera, 32 family, 32 order, 3 classes, based on taxonomic system proposed by Round et al. (1990). We described the taxonomic informations of diatom, illustrations, classification, references, basionym, synonym and distribution.

Division Bacillariophyta

Class Bacillariophyceae Haeckel 1878

Subclass Bacillariophycidae Mann 1990

Order Achnanthales Silva 1962

Family Achnanthaceae Kützing 1844

Family Achnanthidiaceae Mann 1990

Family Cocconeidaceae Kützing 1844

Order Bacillariales Hendey 1937

Family Bacillariaceae Ehrenberg 1831

Order Cymbellales Mann 1990

Family Cymbellaceae Greville 1833

Order Naviculales Bessey 1907

Family Amphipleuraceae Grunow 1862

Family Berkeleyaceae Mann 1990

Parlibellus berkeleyi (Kützing) Cox 1988

Parlibellus rhombiformis (Hustedt) Cox 1988

Family Diploneidaceae Mann 1990

Family Naviculaceae Kützing 1844

Family Pleurosigmataceae Mereschowsky 1903

Order Surirellales Mann 1990

Family Surirellaceae Kützing 1844

Subclass Fragilariophycidae Round 1990

Order Fragilariales Silva 1962

Family Fragilariaceae Greville 1833

Order Licmophorales Round 1990

Family Licmophoraceae Kützing 1844

Licmophora flabellata (Grev) Agardh 1831

Licmophora paradoxa (Lyngbye) Agardh 1828

Order Rhaponeidales Round 1990

Family Rhaphoneidaceae Forti 1912

Order Thalassionematales Round 1990

Family Thalassionemataceae Round 1990

Thalassionema nitzschioides (Grunow) Mereschkowsky 1902

Class Coscinodiscophyceae Round & Crawford 1990

Subclass Coscinodiscophycidae Round & Crawford 1990

Order Coscinodiscales Round & Crawford 1990

Family Coscinodiscaceae Kützing 1844

Family Heliopeltaceae Smith 1872

Family Hemidiscaceae Hendey 1937

Order Melosirales Crawford 1990

Family Hyalodiscaceae Crawford 1990

Family Melosiraceae Kützing 1844

Family Stephanopyxidaceae Nikolaev

Order Paraliales

Family Paraliaceae Crawford 1990

Subclass Rhizosoleniophycidae Round & Crawford 1990

Order Rhizosoleniales Silva 1962

Family Rhizosoleniaceae De Toni 1890

Class Mediophyceae (Jousé & Proshkina-Lavrenko) Medlin & Kaczmarska 2004

Subclass Biddulphiophycidae Round & Crawford 1990

Order Biddulphiales Krieger 1954

Family Biddulphiaceae Kützing 1844

Order Hemiaulales Round & Crawford 1990

Family Hemiaulaceae Heiberg 1863

Order Triceratiales Round & Crawford 1990

Family Triceratiaceae (Schütt) Lemmermann 1899

Subclass Chaetocerotophycidae Round & Crawford 1990

Order Chaetocerotales Round & Crawford 1990

Family Chaetocerotaceae Ralfs 1861

Subclass Cymatosirophycidae Round & Crawford 1990

Order Cymatosirales Round & Crawford 1990

Family Cymatosiraceae Hasle, von Stosch & Syvertsen 1983

Subclass Lithodesmiophycidae Round & Crawford 1990

Order Lithodesmiales Round & Crawford 1990

Family Lithodesmiaceae Round 1990

Subclass Thalassiosirophycidae Round & Crawford 1990

Order Thalassiosirales Glezer & Makarova 1986

Family Skeletonemataceae Lebour 1930

Family Stephanodiscaceae Glezer & Makarova 1986

Family Thalassiosiraceae Lebour 1930

Achnanthes brevipes Agardh 1824 (Fig. 1a)

Fig. 1.Light microscopy (a, b, d-h, j, k, m-p, r, s, u) and scanning electron microscopy (c, i, l, q, t) microphotographs. (a) Achnanthes brevipes. (b) Achnanthes groenlandica. (c) Achnanthes longipes. (d) Achnanthes subconstricta. (e) Planothidium septentrionalis. (f) Cocconeis pseudomarginata. (g) Cocconeis scutellum. (h) Cocconeis stauroneiformis. (i) Bacillaria paxillifera. (j) Hantzschia virgata. (k) Nitzschia bilobata. (l) Nitzschia valdestriata. (m) Pseudo-nitzschia pungens. (n) Tryblionella acuminate. (o) Tryblionella coarctata. (p) Cymbella aspera. (q) Halamphora coffeiformis. (r) Parlibellus berkeleyi. (s) Parlibellus rhombiformis. (t) Diploneis weissflogii. (u) Meuniera membranacea. Scale bars represent: a-d, f-k, m-p, r, s, u, 10 μm; e, t, 5 μm; l, 1 μm; q, 2 μm.

Synonyms: Achnantella brevipes (Agardh) Gaillon 1833; Achnanthidium brevipes (Agardh) Heiberg 1863; Achnanthidium brevipes (Agardh) Cleve 1895; Achnanthes recava Hohn & Hellerman 1966.

References: Agardh 1824, p. 1; Gaillon 1833, p. 10; Heiberg 1863, p. 118; Cleve 1895, p. 193; Hendey 1951, p. 41, pl. 16, figs. 9, 10; Hohn and Hellerman 1966, p. 117, pl. I, figs. 7, 8.

Specimen examined: slide LJH2014080007 in Sangmyung University, Seoul.

Occurrence: Achananthes brevipes was observed at BI-02 on 11 Aug 2014 and BI-03 on 23 Apr 2015 (Table 2).

Table 2.Check-list of diatom speices from the three islands in Korea

Table 2.*Station numbers correspond to Table 1.

Achnanthes groenlandica Cleve & Grunow 1880 (Fig. 1b)

Basionym: Achnanthidium groenlandicum Cleve 1873.

Synonyms: Achnanthidium groenlandicum Cleve 1873; Achnanthepyla groenlandica Peragallo 1921.

References: Cleve and Grunow 1880, p. 20; Peragallo 1921, p. 10; Cleve 1873, p. 25, pl. 4, fig. 23.

Specimen examined: slide LJH2014080002 in Sangmyung University, Seoul.

Occurrence: Achnanthes groenlandica was observed at BI-03 on 12 Aug 2014 and DI-02 on 22 Apr 2015 (Table 2).

Achnanthes longipes Agardh 1824 (Fig. 1c)

Synonym: Achnantella longipes Gaillon 1833.

References: Agardh 1824, p. 1; Gaillon 1833, p. 10.

Specimen examined: stub LJH2014081022 in Sangmyung University, Seoul.

Occurrence: Achnanthes longipes was observed at BI-01 on 11 Aug 2014 and BI-04 on 12 Aug 2014 (Table 2).

Achnanthes subconstricta (Meister) Toyoda 2003 (Fig. 1d)

Basionym: Achnanthes javanica var. subconstricta Meister 1932.

References: Toyoda et al. 2003, p. 369; Meister 1932, p. 40, pl. 14, fig. 113.

Specimen examined: slide LJH2014080018 in Sangmyung University, Seoul.

Occurrence: Achnanthes subconstricta was observed at BI-03 on 12 Aug 2014 (Table 2).

Planothidium septentrionalis (Østrup) Round & Bukhtiyarova 1996 (Fig. 1e)

Basionym: Achnanthes septentrionalis Østrup 1910.

Synonyms: Achnanthes septentrionalis Østrup 1910; Achnanthes delicatula subsp. septentrionalis (Østrup) Lange-Bertalot & Krammer 1987; Achnantheiopsis septentrionalis (Østrup) Lange-Bertalot 1997.

References: Østrup 1910, p. 215, pl. 13, fig. 21; Lange-Bertalot and Krammer 1987, p. 46, pl. 80, figs. 24-31, pl. 82, figs. 1-24, pl. 90, figs. 3, 4; Round and Bukhtiyarova 1996, p. 353; Lange-Bertalot 1997, p. 208.

Specimen examined: slide LJH2014080023 in Sangmyung University, Seoul.

Occurrence: Planothidium septentrionalis was observed at BI-03 on 12 Aug 2014 (Table 2).

Cocconeis pseudomarginata Gregory 1857 (Fig. 1f)

References: Gregory 1857, p. 492, pl. 9, fig. 27.

Specimen examined: slide LJH2014080022 in Sangmyung University, Seoul.

Occurrence: Cocconeis pseudomarginata was observed at BI-04 on 12 Aug 2014 (Table 2).

Cocconeis scutellum Ehrenberg 1838 (Fig. 1g)

References: Ehrenberg 1838, p. 194, pl. 14, fig. 8.

Specimen examined: slide LJH2014080018 in Sangmyung University, Seoul.

Occurrence: Cocconeis scutellum was observed at BI-03 on 12 Aug 2014 (Table 2).

Cocconeis stauroneiformis (Smith) Okuno 1957 (Fig. 1h)

Basionym: Cocconeis scutellum var. stauroneiformis Smith 1853.

Synonyms: Cocconeis scutellum var. stauroneiformis Rabenhorst 1864; Cocconeis scutellum var. stauroneiformis Van Heurck 1880.

References: Smith 1853; Rabenhorst 1864, p. 101; Van Heurck 1880, pl. 29, figs. 10, 11; Okuno 1957, p. 217, pl. 6, fig. 2.

Specimen examined: slide LJH2014080017 in Sangmyung University, Seoul.

Occurrence: Cocconeis stauroneiformis was observed at BI-02 on 11 Aug 2014 (Table 2).

Bacillaria paxillifera (Müller) Marsson 1901 (Fig. 1i)

Basionym: Vibrio paxillifer Müller 1786.

Synonyms: Bacillaria paradoxa Gmelin 1791; Oscillaria paxillifera (Müller) Schrank 1823; Oscillatoria paxillifer (Müller) Schrank 1823; Diatoma paxillifera (Müller) Brébisson 1838; Nitzschia paxillifer (Müller) Heiberg 1863; Nitzschia paradoxa (Gmelin) Grunow 1880; Oscillatoria paxillifera (Müller) Gomont 1892; Bacillaria paxillifer (Müller) Marsson 1901.

References: Müller 1786, p. 54, pl. 7, figs. 3-7; Gmelin 1791, p. 3903; Schrank 1823, p. 539; Brébisson 1838, p. 12; Heiberg 1863, p. 113; Cleve and Grunow 1880, p. 85; Gomont 1892, p. 239; Marsson 1901, p. 254; Elmore 1921, p. 143, pl. 20, figs. 761-763.

Specimen examined: stub LJH2014081005 in Sangmyung University, Seoul.

Occurrence: Bacillaria paxillifera was observed on 11 Aug 2014 (DI-01, DI-02, SI-01, DI-04, BI-02), 12 Aug 2014 (BI-03, BI-04, BI-05), and 23 Apr 2015 (BI-03, BI-04) (Table 2).

Hantzschia virgata (Roper) Cleve & Grunow 1880 (Fig. 1j)

Basionym: Nitzschia virgata Roper 1858.

Synonym: Nitzschia virgata Roper 1858.

References: Roper 1858, p. 23, pl. 3, fig. 6; Cleve and Grunow 1880, p. 104; Kuntze 1898, p. 409.

Specimen examined: slide LJH2014080009 in Sangmyung University, Seoul.

Occurrence: Hantzschia virgata was observed at BI-02 on 11 Aug 2014 and BI-04 on 12 Aug 2014 (Table 2).

Nitzschia bilobata Smith 1853 (Fig. 1k)

References: Smith 1853, p. 42, pl. 15, fig. 113.

Specimen examined: slide LJH2014080023 in Sangmyung University, Seoul.

Occurrence: Nitzschia bilobata was observed at BI-03 on 12 Aug 2014 (Table 2).

Nitzschia valdestriata Aleem & Hustedt 1951 (Fig. 1l)

References: Aleem and Hustedt 1951, p. 19, fig. 5a-b.

Specimen examined: stub LJH2014081023 in Sangmyung University, Seoul.

Occurrence: Nitzschia valdestriata was observed at BI-03 on 12 Aug 2014 (Table 2).

Pseudo-nitzschia pungens (Grunow ex Cleve) Hasle 1993 (Fig. 1m)

Basionym: Nitzschia pungens Grunow ex Cleve 1897.

Synonym: Nitzschia pungens Grunow ex Cleve 1897.

References: Cleve 1897, p. 24, pl. 2, fig. 23; Hasle 1993, p. 319.

Specimen examined: slide LJH2014080001 in Sangmyung University, Seoul.

Occurrence: Pseudo-nitzschia pungens was observed on 11 Aug 2014 (DI-01, DI-02, DI-03, DI-04, BI-01, BI-02), 12 Aug 2014 (BI-03, BI-04) (Table 2).

Tryblionella acuminata Smith 1853 (Fig. 1n)

Synonym: Nitzschia acuminata (W.Smith) Grunow 1878.

References: Smith 1853, p. 36, pl. 10, fig. 77; Grunow 1878, p. 73.

Specimen examined: slide LJH2014080025 in Sangmyung University, Seoul.

Occurrence: Tryblionella acuminata was observed on 11 Aug 2014 (DI-01, DI-02, DI-03, DI-04, BI-01), 12 Aug 2014 (BI-03, BI-04, BI-05) (Table 2).

Tryblionella coarctata (Grunow in Cleve & Grunow) Mann in Round, Crawford & Mann 1990(Fig. 1o)

Basionym: Nitzschia coarctata Grunow 1880.

Synonym: Nitzschia coarctata Grunow 1880.

References: Grunow 1880, p. 68; Round et al. 1990, p. 678.

Specimen examined: slide LJH2014080018 in Sangmyung University, Seoul.

Occurrence: Tryblionella coarctata was observed at DI-01 on 11 Aug 2014 and BI-03 on 12 Aug 2014 (Table 2).

Cymbella aspera (Ehrenberg) Cleve 1894 (Fig. 1p)

Basionym: Cocconema asperum Ehrenberg 1840.

Synonyms: Frustulia gastroides Kützing 1833; Cocconema asperum Ehrenberg 1840; Cymbella gastroides (Kützing) Kützing 1844; Cymbella lanceolata var. aspera (Ehrenberg) Brun 1880.

References: Kützing 1833, p. 543, pl.13, fig. 9; Ehrenberg 1840, p. 206; Kützing 1844, p. 79, pl. 6, fig. 4b; Brun 1880, p. 57, pl. 9, fig. 16; Cleve 1894, p. 175.

Specimen examined: slide LJH2014080023 in Sangmyung University, Seoul.

Occurrence: Cymbella aspera was observed at BI-03 on 12 Aug 2014 (Table 2).

Halamphora coffeiformis (Agardh) Levkov 2009 (Fig. 1q)

Basionym: Frustulia coffeiformis Agardh 1827.

Synonyms: Frustulia coffeiformis Agardh 1827; Amphora coffeiformis (Agardh) Kützing 1844; Amphora salina Smith 1853; Amphora coffeaeformis var. salina (Smith) Schönfeldt 1907; Amphora paulii Patrick 1970.

References: Agardh 1827, p. 627; Kützing 1844, p. 108, pl. 5, fig. 37; Smith 1853, p. 19, pl. 30, fig. 251; Schönfeldt 1907, p. 211; Levkov 2009, p. 179, pl. 91, figs. 1-14, pl. 94, figs. 17-27, pl. 99, figs. 15-23.

Specimen examined: stub LJH2014080017 in Sangmyung University, Seoul.

Occurrence: Halamphora coffeiformis was observed at BI-02 on 11 Aug 2014 (Table 2).

Parlibellus berkeleyi (Kützing) Cox 1988 (Fig. 1r)

Basionym: Micromega berkeleyi Kützing 1849.

Synonym: Micromega berkeleyi Kützing 1849.

References: Kützing 1849, p. 106; Cox 1988, p. 21, figs. 6-10, 16.

Specimen examined: slide LJH2014080017 in Sangmyung University, Seoul.

Occurrence: Parlibellus berkeleyi was observed at BI-02 on 11 Aug 2014 (Table 2).

Parlibellus rhombiformis (Hustedt) Cox 1988 (Fig. 1s)

Basionym: Navicula rhombiformis Hustedt 1944.

Synonym: Navicula rhombiformis Hustedt 1944.

References: Hustedt 1944, p. 273, fig. 6; Cox 1988, p. 25.

Specimen examined: slide LJH2014080019 in Sangmyung University, Seoul.

Occurrence: Parlibellus rhombiformis was observed at BI-04 on 12 Aug 2014 (Table 2).

Diploneis weissflogii Cleve 1894 (Fig. 1t)

Basionym: Navicula weissflogii Schmidt 1873.

Synonym: Navicula weissflogii Schmidt 1873.

References: Schmidt 1873, p. 406, pl. 6, figs. 3, 4; Cleve 1894, p. 91.

Specimen examined: stub LJH2014081021 in Sangmyung University, Seoul.

Occurrence: Diploneis weissflogii was observed at BI-05 on 12 Aug 2014 (Table 2).

Meuniera membranacea (Cleve) Silva in Hasle & Syvertsen 1996 (Fig. 1u)

Basionym: Navicula membranacea Cleve 1897.

Synonyms: Stauropsis membranacea (Cleve) Meunier 1910; Stauroneis membranacea (Cleve) Hustedt 1959.

References: Cleve 1897, p. 24, pl. 2, figs. 25-28; Meunier 1910, p. 319, pl. 33, figs. 37-40; Hustedt 1959, p. 833, fig. 1176; Hasle and Syvertsen 1996, pp 273, 339.

Specimen examined: slide LJH2014080006 in Sangmyung University, Seoul.

Occurrence: Meuniera membranacea was observed on 11 Aug 2014 (DI-01, DI-02, DI-03, DI-04, BI-01, SI-01), 12 Aug 2014 (BI-03, BI-05) (Table 2).

Navicula directa (Smith) Ralfs in Pritchard 1861 (Fig. 2a)

Fig. 2.Light microscopy (a, d-f, h-k, m, s) and scanning electron microscopy (b, c, g, l, n-r) microphotographs. (a) Navicula directa. (b) Navicula gregaria. (c) Navicula perminuta. (d) Trachyneis aspera. (e) Carinasigma rectum. (f ) Gyrosigma fasciola. (g) Gyrosigma littorale. (h-j) Gyrosigma obscurum. (k) Pleurosigma aestuarii. (l) Pleurosigma amara. (m) Pleurosigma angulatum. (n-p) Pleurosigma frenguellianum. (q-r) Pleurosigma inflatum. (s) Pleurosigma rigidum. Scale bars represent: a, d, e-k, m, q-s, 10 μm; b, o, p, 5 μm; c, 1 μm; l, n, 20 μm.

Basionym: Pinnularia directa Smith 1853.

Synonym: Pinnularia directa Smith 1853.

References: Smith 1853, p. 56, pl. 18, fig. 172; Pritchard 1861, p. 906.

Specimen examined: stub LJH2014081015 in Sangmyung University, Seoul.

Occurrence: Navicula directa was observed at DI-04 on 11 Aug. 2014 (Table 2).

Navicula gregaria Donkin 1861 (Fig. 2b)

Synonym: Schizonema gregarium (Donkin) Kuntze 1898.

References: Donkin 1861, p. 10, pl. 1, fig. 10; Kuntze 1898, p. 553.

Specimen examined: slide LJH2014080023 in Sangmyung University, Seoul.

Occurrence: Navicula gregaria was observed at BI-03 on 12 Aug 2014 (Table 2).

Navicula perminuta Grunow in Van Heurck 1880 (Fig. 2c)

Synonyms: Navicula cryptocephala var. perminuta (Grunow) Cleve 1895; Navicula diserta Hustedt 1939; Navicula mendotia VanLandingham 1975.

References: Van Heurck 1880, p. pl. 14, fig. 7; Cleve 1895, p. 14; Hustedt 1939, p. 627, figs. 78-79; Van Landingham 1975, p. 102, pl. 7, fig. 7.

Specimen examined: stub LJH2014081001 in Sangmyung University, Seoul.

Occurrence: Navicula perminuta was observed at DI-01, DI-02, DI-03, DI-04, SI-01 on 22 Apr 2015 and BI-01 on 23 Apr 2015 (Table 2).

Trachyneis aspera (Ehrenberg) Cleve 1894 (Fig. 2d)

Basionym: Navicula aspera Ehrenberg 1840.

Synonyms: Navicula aspera Ehrenberg 1840; Stauroptera aspera Ehrenberg 1841; Stauroneis aspera (Ehrenberg) Kützing 1844; Stauroneis achnanthes (Ehrenberg) Kützing 1844; Stauroneis pulchella Smith 1853; Schizonema asperum (Ehrenberg) Kuntze 1898.

References: Ehrenberg 1840, p. 213; Ehrenberg 1841, p. 135; Kützing 1844, p. 106, pl. 29, fig. 12, p. 106, pl. 29, figs. 20, 22; Smith 1853, p. 61, pl. 19, fig. 194; Cleve 1894, p. 191; Kuntze 1898, p. 551.

Specimen examined: slide LJH2014080025 in Sangmyung University, Seoul.

Occurrence: Trachyneis aspera was observed on 11 Aug 2014 (DI-01, DI-02, DI-04, BI-01), 12 Aug 2014 (BI-03), 22 Apr 2015 (DI-01) (Table 2).

Carinasigma rectum (Donkin) Reid 2012 (Fig. 2e)

Basionym: Pleurosigma rectum Donkin 1858.

Synonyms: Pleurosigma rectum Donkin 1858; Gyrosigma rectum (Donkin) Cleve 1894.

References: Donkin 1858, p. 23, pl. 3, fig. 6; Cleve 1894, p. 119; Reid 2012, p. 96, pl. 19, fig. 9.

Specimen examined: slide LJH2014080007 in Sangmyung University, Seoul.

Occurrence: Carinasigma rectum was observed at BI-02 on 11 Aug 2014 (Table 2).

Gyrosigma fasciola (Ehrenberg) Griffith & Henfrey 1856 (Fig. 2f)

Basionym: Ceratoneis fasciola Ehrenberg 1839.

Synonyms: Ceratoneis fasciola Ehrenberg 1839; Pleurosigma fasciola (Ehrenberg) Smith 1852; Scalptrum fasciolum (Ehrenberg) Kuntze 1891.

References: Ehrenberg 1839, p. 157; Smith 1852, p. 9, pl. 2, fig. 6; Griffith and Henfrey 1856, p. 303, pl. 11, fig. 21; Kuntze 1891, p. 919.

Specimen examined: slide LJH2014080018 in Sangmyung University, Seoul.

Occurrence: Gyrosigma fasciola was observed at BI-03 on 12 Aug 2014 (Table 2).

Gyrosigma littorale (Smith) Griffith & Henfrey 1856 (Fig. 2g)

Basionym: Pleurosigma littorale Smith 1852.

Synonyms: Pleurosigma littorale Smith 1852; Scalprum (Scalptrum) litorale (Smith) 1891; Gyrosigma litorale (Smith) Cleve 1894.

References: Smith 1852, p. 10, pl. 2, fig. 8; Griffith and Henfrey 1856, p. 303, pl. 11, fig. 19; Kuntze 1891, p. 919; Cleve 1894, p. 116.

Specimen examined: stub LJH2014081023 in Sangmyung University, Seoul.

Occurrence: Gyrosigma littorale was observed at BI-03 on 12 Aug 2014 (Table 2).

Gyrosigma obscurum (Smith) Griffith & Henfrey 1856 (Fig. 2h-2j)

Valves vaulted, slightly linear, sigmoid, tapering to obtuse apices. Lenth 120–130 µm, width 11–12 µm with perpendicular striae. Central area slightly convex with elliptical raphe nodule, and narrow central bars.

Basionym: Pleurosigma obscurum Smith 1852.

Synonyms: Pleurosigma obscurum Smith 1852; Scalptrum obscurum (Smith) Kuntze 1891.

References: Smith 1852, p. 8, pl. 1, fig. 11; Griffith and Henfrey 1856, p. 302, pl. 11, fig. 27; Kuntze 1891, p. 919.

Specimen examined: slide NIBRDI0000134567 in National Institute of Biological Resources (NIBR), Incheon.

Occurrence: Gyrosigma obscurum was observed at BI-03 on 23 Apr 2015 (Table 2).

Pleurosigma aestuarii (Brébisson ex Kützing) Smith 1853 (Fig. 2k)

Basionym: Navicula aestuarii Brébisson ex Kützing 1849.

Synonyms: Navicula aestuarii Brébisson ex Kützing 1849; Gyrosigma aestuarii (Brébisson ex Kützing) Griffith & Henfrey 1856; Pleurosigma angulatum var. aestuarii Brébisson) van Heurck 1885.

References: Smith 1853, p. 65, pl. 31, fig. 275; Kützing 1849, p. 890; Griffith and Henfrey 1856, p. 302, pl. 11, fig. 35; Van Heurck 1885, p. 115.

Specimen examined: slide LJH2014080024 in Sangmyung University, Seoul.

Occurrence: Pleurosigma aestuarii was observed on 11 Aug 2014 (DI-01, DI-02, DI-03, DI-04, BI-01, BI-02), 12 Aug 2014 (BI-03, BI-05) (Table 2).

Pleurosigma amara Stidolph 1992 (Fig. 2l)

References: Stidolph 1992, p. 349, figs. 44-51.

Specimen examined: stub LJH2015041008 in Sangmyung University, Seoul.

Occurrence: Pleurosigma amara was observed at BI-03 on 23 Apr 2015 (Table 2).

Pleurosigma angulatum (Quekett) Smith 1852 (Fig. 2m)

Basionym: Navicula angulata Quekett 1848.

Synonym: Navicula angulata Quekett 1848.

References: Quekett 1848, p. 438, pl. 8, figs. 4-7; Smith 1852, p. 7, pl. 1, fig. 8.

Specimen examined: slide LJH2015040027 in Sangmyung University, Seoul.

Occurrence: Pleurosigma angulatum was observed at BI-02 on 11 Aug 2014 (Table 2).

Pleurosigma frenguellianum Sunesen, Sterrenburg & Sar 2014 (Fig. 2n-2p)

Valves linear-lanceolate, sigmoid, with slightly acute apices. Lenth 200–210 µm, width 20–22 µm. Transverse striae 22-25 in 10 µm, longitudinal striae 22–25 in 10 µm with diagonal striae. Raphe sternum single curvature, narrow, thickened, almost central, and sigmoid towards the apices. Central area slightly raised and convex with narrow central bars, surrounding the elliptical raphe nodule. No central hyaline arear. Polar endings with well-developed helictoglossa, slightly turned towards the concave side of the valve. Apices with one or two isolated pores around the helictoglossa.

References: Sar et al. 2014, pp 157-160, figs. 25-47.

Specimen examined: slide NIBRDI0000134569 in National Institute of Biological Resources (NIBR), Incheon.

Occurrence: Pleurosigma frenguellianum was observed at BI-03 on 23 Apr 2015 (Table 2).

Pleurosigma inflatum Shadbolt 1853 (Fig. 2q-2r)

Synonyms: Pleurosigma naviculaceum Brébisson 1854, Pleurosigma transversale Smith 1856.

References: Shadbolt 1853, p. 16, pl. I, fig. 9; Brébisson 1854, p. 255, fig. 7; Smith 1856, p. 96.

Specimen examined: stub LJH2015041021 in Sangmyung University, Seoul.

Occurrence: Pleurosigma inflatum was observed at DI-01 on 22 Apr 2015 (Table 2).

Pleurosigma rigidum Smith 1853 (Fig. 2s)

Synonyms: Gyrosigma rigidum (Smith) Griffith & Henfrey 1856; Scalprum (Scalptrum) rigidum (Smith) Kuntze 1891.

References: Smith 1853, p. 64, pl. 20, fig. 198; Griffith and Henfrey 1856, p. 302, pl. 11, fig. 30; Kuntze 1891, p. 919.

Specimen examined: slide LJH2014080015 in Sangmyung University, Seoul.

Occurrence: Pleurosigma rigidum was observed on 11 Aug 2014 (DI-03, DI-04, SI-01, BI-01, BI-02), 12 Aug 2014 (BI-03) (Table 2).

Pleurosigma sabangi Meister 1932 (Fig. 3a-3c)

Fig. 3Light microscopy (a-c, e, j, m) and scanning electron microscopy (d, f, g, h, i, k, l, n, o) microphotographs. (a-c) Pleurosigma sabangi. (d) Pleurosigma tenuiforme. (e) Petrodictyon gemmoides. (f, g) Asterionellopsis glacialis. (h, i) Ceratoneis closterium. (j) Tabularia fasciculata. (k, l) Licmophora flabellata. (m) Licmophora paradoxa. (n, o) Delphineis minutissima. Scale bars represent: a-c, e, f, h, k, m, 10 μm; d, 20 μm; g, l, n, o, 2 μm; i, 1 μm; j, 5 μm.

Valves sigmoid, with strongly convex outline and slightly round apices. Lenth 200–220 µm, width 28–32 µm. Transverse striae 20-22 in 10 µm, longitudinal striae 20–22 in 10 µm with diagonal striae. Raphe sternum single curvature, narrow, thickened, sigmoid towards the apices. The raphe sternum located central in central area on the valve but located convex side on the valve toward apices. Central area slightly convex. No central hyaline arear.

References: Meister 1932, p. 32, figs. 77, 78.

Specimen examined: slide NIBRDI0000134568 in National Institute of Biological Resources (NIBR), Incheon.

Occurrence: Pleurosigma sabangi was observed at BI-03 on 23 Apr 2015 (Table 2).

Pleurosigma tenuiforme Quillfeldt 2000 (Fig. 3d)

References: Quillfeldt 2000, p. 222, figs. 1-7.

Specimen examined: stub LJH2015041030 in Sangmyung University, Seoul.

Occurrence: Pleurosigma tenuiforme was observed at BI-03, BI-05 on 23 Apr 2015 (Table 2).

Petrodictyon gemmoides (Østrup) Mann in Round, Crawford & Mann 1990(Fig. 3e)

Basionym: Surirella gemmoides Østrup 1897.

Synonym: Surirella gemmoides Østrup 1897.

References: Østrup 1897, p. 277, pl. 1, fig. 14; Round et al. 1990, p. 674.

Specimen examined: slide LJH2014080024 in Sangmyung University, Seoul.

Occurrence: Petrodictyon gemmoides was observed at BI-02 on 11 Aug 2014 (Table 2).

Asterionellopsis glacialis (Castracane) Round, Crawford & Mann 1990(Fig. 3f and 3g)

Basionym: Asterionella glacialis Castracane 1886.

Synonym: Asterionella glacialis Castracane 1886.

References: Castracane 1886, p. 50, pl. 14, fig. 1; Round et al. 1990, p. 664.

Specimen examined: stub LJH2014081026 in Sangmyung University, Seoul.

Occurrence: Asterionellopsis glacialis was observed at DI-03, DI-04 on 11 Aug 2014, BI-04 on 12 Aug 2014 and BI-03, BI-04 on 23 Apr 2015 (Table 2).

Ceratoneis closterium Ehrenberg 1839 (Fig. 3h and 3i)

Synonyms: Nitzschia closterium (Ehrenberg) Smith 1853; Nitzschiella closterium (Ehrenberg) Rabenhorst 1864; Nitzschia longissima var. closterium (Ehrenberg) Van Heurck 1885.

References: Ehrenberg 1839, p. 157; Smith 1853, p. 42, pl. 15, fig. 120; Rabenhorst 1864, p. 163; Van Heurck 1885, p. 185; Kuntze 1898, p. 410.

Specimen examined: stub LJH2014081023 in Sangmyung University, Seoul.

Occurrence: Ceratoneis closterium was observed at DI-02, DI-03 on 11 Aug 2014 and BI-03 on 12 Aug 2014 (Table 2).

Tabularia fasciculata (Agardh) Williams & Round 1986 (Fig. 3j)

Basionym: Diatoma fasciculata Agardh 1812.

Synonyms: Lyngbyea fasciculata (Agardh) Sommerfelt 1826; Exilaria fasciculata (Agardh) Greville 1827; Exilaria fasciculata Kützing 1833; Fragilaria fasciculata (Agardh) Lange-Bertalot 1980; Diatoma fasciculata Agardh 1812; Diatoma tabulata Agardh 1832; Synedra affinis Kützing 1844; Synedra tabulata (Agardh) Kützing 1844; Synedra ridica Hohn & Hellerman 1966.

References: Agardh 1812, p. 35; Sommerfelt 1826, p. 190; Williams and Round 1986, p. 326, figs. 46-52; Greville 1827, pl. 291; Kützing 1833, p. 561, fig. 40; Lange-Bertalot 1980, p. 750; Agardh 1832, p. 50; Kützing 1844, p. 68, pl.15, figs. 6, 10, 11; Hohn and Hellerman 1966, p. 130, pl. 2, fig. 24.

Specimen examined: slide LJH2014080008 in Sangmyung University, Seoul.

Occurrence: Tabularia fasciculata was observed at BI-03 on 12 Aug 2014 (Table 2).

Licmophora flabellata (Greville) Agardh 1831 (Fig. 3k and 3l)

Basionym: Exilaria flabellata Greville 1827.

Synonym: Exilaria flabellata Greville 1827.

References: Greville 1827, pl. 289; Agardh 1831, p. 42.

Specimen examined: stub LJH2015041008 in Sangmyung University, Seoul.

Occurrence: Licmophora flabellata was observed at BI-03 on 23 Apr 2015 (Table 2).

Licmophora paradoxa (Lyngbye) Agardh 1828 (Fig. 3m)

Basionym: Echinella paradoxa Lyngbye 1819.

Synonym: Echinella paradoxa Lyngbye 1819.

References: Lyngbye 1819, p. 211; Agardh 1828, p. 32.

Specimen examined: slide LJH2014080024 in Sangmyung University, Seoul.

Occurrence: Licmophora paradoxa was observed at BI-02 on 11 Aug 2014 and BI-03 on 12 Aug 2014 (Table 2).

Delphineis minutissima (Hustedt) Simonsen 1987 (Fig. 3n and 3o)

Basionym: Rhaphoneis minutissima Hustedt 1939.

Synonym: Rhaphoneis minutissima Hustedt 1939.

References: Hustedt 1939, p. 599, figs. 14, 15; Simonsen 1987, p. 252; Sar et al. 2007, p. 72, fig. 5A-J.

Specimen examined: stub LJH2014081008 in Sangmyung University, Seoul.

Occurrence: Delphineis minutissima was observed at BI-03 on 12 Aug 2014 (Table 2).

Thalassionema nitzschioides (Grunow) Mereschkowsky 1902 (Fig. 4a)

Fig. 4.Light microscopy (a-e, h, j-p) and scanning electron microscopy (f, g, i) microphotographs. (a) Thalassionema nitzschioides. (b) Coscinodiscopsis commutate. (c) Coscinodiscopsis jonesiana. (d, e) Coscinodiscus asteromphalus. (f, g) Coscinodiscus centralis. (h) Coscinodiscus granii. (i) Coscinodiscus radiatus. (j) Coscinodiscus wailesii. (k) Actinoptychus senarius. (l) Actinoptychus splendens. (m) Actinocyclus curvatulus. (n) Actinocyclus normanii. (o) Actinocyclus octonarius var. octonarius. (p) Actinocyclus octonarius var. ralfsii. Scale bars represent: a-e, g-p, 10 μm; f, 50 μm.

Basionym: Synedra nitzschioides Grunow 1862.

Synonyms: Synedra nitzschioides var. minor Cleve 1883; Thalassiothrix curvata Castracane 1886.

References: Cleve 1883, p. 482; Castracane 1886, p. 55, pl. 24, fig. 6; Mereschkowsky 1902, p. 78.

Specimen examined: slide LJH2014080005 in Sangmyung University, Seoul.

Occurrence: Thalassionema nitzschioides was observed at BI-04 on 12 Aug 2014 and DI-01, DI-04 on 22 Apr 2015 (Table 2).

Coscinodiscopsis commutata (Grunow) Sar & Sunesen in Sar et al. 2008(Fig. 4b)

Basionym: Coscinodiscus commutatus Grunow 1884.

Synonyms: Coscinodiscus commutatus Grunow 1884; Coscinodiscus jonesianus var. commutata (Grunow) Hustedt 1928.

References: Grunow 1884, p. 79; Sar et al. 2008, p. 418.

Specimen examined: slide LJH2014080030 in Sangmyung University, Seoul.

Occurrence: Coscinodiscopsis commutata was observed at BI-01, DI-02 on 11 Aug 2014 and DI-01 on 22 Apr 2015 (Table 2).

Coscinodiscopsis jonesiana (Greville) Sar & Sunesen in Sar et al. 2008(Fig. 4c)

Basionym: Eupodiscus jonesianus Greville 1862

Synonym: Eupodiscus jonesianus Greville 1862.

References: Greville 1862, p. 22, pl. 2, fig. 3; Sar et al. 2008, p. 418.

Specimen examined: slide LJH2014080027 in Sangmyung University, Seoul.

Occurrence: Coscinodiscopsis jonesiana was observed at DI-03 on 11 Aug 2014 (Table 2).

Coscinodiscus asteromphalus Ehrenberg 1844 (Fig. 4d and 4e)

Synonym: Coscinodiscus asteromphalus var. genuina Grunow 1884.

References: Ehrenberg 1844, p. 77; Grunow 1884, p. 78.

Specimen examined: slide LJH2015040019 in Sangmyung University, Seoul.

Occurrence: Coscinodiscus asteromphalus was observed at DI-01, DI-02 on 22 Apr 2015 (Table 2).

Coscinodiscus centralis Ehrenberg 1844 (Fig. 4f and 4g)

Synonyms: Coscinodiscus asteromphalus var. centralis

Grunow 1884; Coscinodiscus oculus-iridis var. tenuistriata Grunow 1884.

References: Ehrenberg 1844, p. 78; Grunow 1884, pp 77, 79.

Specimen examined: stub LJH2014081018 in Sangmyung University, Seoul.

Occurrence: Coscinodiscus centralis was observed on 11 Aug 2014 (BI-01, DI-02, DI-04, SI-01), 12 Aug 2014 (BI-03), 22 Apr 2015 (DI-01) and 23 Apr 2015 (BI-02, BI-03) (Table 2).

Coscinodiscus granii Gough 1905 (Fig. 4h)

References: Gough 1905, p. 338, fig. 3b.

Specimen examined: slide LJH2014080029 in Sangmyung University, Seoul.

Occurrence: Coscinodiscus granii was observed at DI-02 on 11 Aug 2014 and BI-03, BI-04 on 12 Aug 2014 (Table 2).

Coscinodiscus radiatus Ehrenberg 1840 (Fig. 4i)

References: Ehrenberg 1840, p. 68, pl. 3, fig. 1a-c.

Specimen examined: stub LJH2014081002 in Sangmyung University, Seoul.

Occurrence: Coscinodiscus radiatus was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-05) and 23 Apr 2015 (BI-03) (Table 2).

Coscinodiscus wailesii Gran & Angst 1931 (Fig. 4j)

References: Gran and Angst 1931, p. 448.

Specimen examined: slide LJH2014080011 in Sangmyung University, Seoul.

Occurrence: Coscinodiscus wailesii was observed on 11 Aug 2014 (BI-01, DI-01, DI-03, DI-04, SI-01) and 12 Aug 2014 (BI-03) (Table 2).

Actinoptychus senarius Ehrenberg 1843 (Fig. 4k)

Basionym: Actinocyclus senarius Ehrenberg 1838.

Synonyms: Actinocyclus senarius Ehrenberg 1838; Actinocyclus undulatus Kützing 1844; Actinoptychus undulatus (Bailey) Ralfs 1861.

References: Ehrenberg 1838, p. 172, pl. 21, fig. 6; Ehrenberg 1843, p. 400, pl. 1.1, fig. 27, pl. 1.3, fig. 21; Kützing 1844, p. 132, pl. 1, fig. 24; Pritchard 1861, p. 839, pl. 5, fig. 88.

Specimen examined: slide LJH2014080024 in Sangmyung University, Seoul.

Occurrence: Actinoptychus senarius was observed on 11 Aug 2014 (BI-02, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-04, BI-05), 22 Apr 2015 (DI-01, DI-02) and 23 Apr 2015 (BI-03, BI-04) (Table 2).

Actinoptychus splendens (Shadbolt) Ralfs ex Pritchard 1861 (Fig. 4l)

Basionym: Actinophaenia splendens Shadbolt 1854.

Synonym: Actinophaenia splendens Shadbolt 1854.

References: Shadbolt 1854, p. 16; Pritchard 1861, p. 840.

Specimen examined: slide LJH2014080017 in Sangmyung University, Seoul.

Occurrence: Actinoptychus splendens was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03), 22 Apr 2015 (DI-02) and 23 Apr 2015 (BI-03) (Table 2).

Actinocyclus curvatulus Janisch in Schmidt 1878 (Fig. 4m)

Synonym: Coscinodiscus curvatulus var. subocellatus Grunow 1884

References: Schmidt 1878, pl. 57, fig. 31; Grunow 1884, p. 83, pl. D, fig. 15.

Specimen examined: slide LJH2014080015 in Sangmyung University, Seoul.

Occurrence: Actinocyclus curvatulus was observed on 11 Aug 2014 (DI-02, DI-04), 12 Aug 2014 (BI-03), and 22 Apr 2015 (DI-01, DI-02) (Table 2).

Actinocyclus normanii (Gregory) Hustedt 1957 (Fig. 4n)

Basionym: Coscinodiscus normanii Gregory ex Greville 1859.

Synonym: Coscinodiscus normanii Gregory ex Greville 1859.

References: Greville 1859, p. 80, pl. 6, fig. 3; Hustedt 1957, p. 218.

Specimen examined: slide LJH2015040019 in Sangmyung University, Seoul.

Occurrence: Actinocyclus normanii was observed at DI-02 on 22 Apr 2015 (Table 2).

Actinocyclus octonarius var. octonarius Ehrenberg 1837 (Fig. 4o)

Synonym: Actinoptychus octonarius (Ehrenberg) Kützing 1844.

References: Ehrenberg 1837, p. 61; Kützing 1844, p. 134, pl. 21, fig. 25.

Specimen examined: slide LJH2014080028 in Sangmyung University, Seoul.

Occurrence: Actinocyclus octonarius var. octonarius was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, SI-01), 12 Aug 2014 (BI-03), and 22 Apr 2015 (DI-01) (Table 2).

Actinocyclus octonarius var. ralfsii (Smith) Hendey 1954 (Fig. 4p)

Basionym: Eupodiscus ralfsii Smith 1856.

Synonyms: Eupodiscus ralfsii Smith 1856; Actinocyclus ralfsii (Smith) Ralfs in Pritchard 1861.

References: Smith 1856, p. 86; Pritchard 1861, p. 835; Hendey 1954, p. 557.

Specimen examined: slide LJH2014080009 in Sangmyung University, Seoul.

Occurrence: Actinocyclus octonarius var. ralfsii was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01) and 12 Aug 2014 (BI-03, BI-04) (Table 2).

Actinocyclus octonarius var. tenellus (Brébisson) Hendey 1954 (Fig. 5a)

Fig. 5.Light microscopy (a-c, e, f, i-k, n, p, r, s) and scanning electron microscopy (d, g, h, l, m, o, q) microphotographs. (a) Actinocyclus octonarius var. tenellus. (b) Actinocyclus vestigulus. (c, d) Roperia tesselata. (e) Hyalodiscus scoticus. (f, g) Podosira stelligera. (h) Melosira nummuloides. (i) Stephanopyxis palmeriana. (j) Stephanopyxis turris. (k, l) Paralia sulcata. (m) Proboscia indica. (n) Rhizosolenia setigera. (o) Rhizosolenia setigera f. pungens. (p, q) Trigonium alternans. (r, s) Cerataulina dentata. Scale bars represent: a-g, i-k, m, o, p, r, s, 10 μm; h, q, l, 5 μm; n, 50 μm.

Basionym: Eupodiscus tenellus Brébisson 1854.

Synonym: Eupodiscus tenellus Brébisson 1854.

References: Brébisson 1854, p. 257, pl. 1, fig. 9; Hendey 1954, p. 557.

Specimen examined: slide LJH2014080004 in Sangmyung University, Seoul.

Occurrence: Actinocyclus octonarius var. tenellus was observed on 11 Aug 2014 (DI-01, DI-02, DI-03, DI-04) and 12 Aug 2014 (BI-03) (Table 2).

Actinocyclus vestigulus Watkins 1986 (Fig. 5b)

References: Watkins and Fryxell 1986, p. 296, figs. 9-16; Hasle and Syvertsen, 1996, p. 123.

Specimen examined: slide LJH2014080012 in Sangmyung University, Seoul.

Occurrence: Actinocyclus vestigulus was observed on 11 Aug 2014 (BI-02, DI-02, DI-04, SI-01) and 12 Aug 2014 (BI-03) (Table 2).

Roperia tesselata (Roper) Grunow ex Pelletan 1889 (Fig. 5c and 5d)

Basionym: Eupodiscus tesselatus Roper 1858.

Synonyms: Eupodiscus tesselatus Roper 1858; Actinocyclus tessellatus (Roper) Ralfs in Pritchard 1861.

References: Roper 1858, p. 19, pl. 3, fig. 1a, b; Pritchard 1861, p. 835; Pelletan 1889, p. 158, fig. 417.

Specimen examined: slide LJH2014080012 and stub LJH2015020019 in Sangmyung University, Seoul.

Occurrence: Roperia tesselata was observed at BI-04 on 12 Aug 2014 and DI-02 on 22 Apr 2015 (Table 2).

Hyalodiscus scoticus (Kützing) Grunow 1879 (Fig. 5e)

Basionym: Cyclotella scotica Kützing 1844.

Synonyms: Cyclotella scotica Kützing 1844; Cycloplea scotica (Kützing) Trevisan 1848.

References: Kützing 1844, p. 50, pl. 1, figs. 2-3; Trevisan 1848, p. 95; Grunow 1879, p. 690, pl. 21, fig. 5.

Specimen examined: slide LJH2014080018 in Sangmyung University, Seoul.

Occurrence: Hyalodiscus scoticus was observed at BI-03 on 12 Aug 2014 (Table 2).

Podosira stelligera (Bailey) Mann 1907 (Fig. 5f and 5g)

Basionym: Hyalodiscus stelliger Bailey 1854.

Synonyms: Hyalodiscus stelliger Bailey 1854; Podosira maculata Smith 1856; Melosira maculata Lagerst 1876.

References: Bailey 1854, p. 7, fig. 10; Smith 1856, p. 54, pl. 49, fig. 328; Lagerstedt 1876, p. 9, fig. 1; Mann 1907, p. 242.

Specimen examined: slide LJH2014080003 and stub LJH2014081014 in Sangmyung University, Seoul.

Occurrence: Podosira stelligera was observed on 11 Aug 2014 (BI-01, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03) and 22 Apr 2015 (DI-01) (Table 2).

Melosira nummuloides (Dillwyn) Agardh 1824 (Fig. 5h)

Basionym: Conferva nummuloides Dillwyn 1809.

Synonyms: Fragilaria nummuloides (Dillwyn) Lyngbye 1819; Conferva nummuloides Dillwyn 1809; Gaillonella nummuloides (Dillwyn) Bory 1831; Lysigonium nummuloides (Dillwyn) Trevisan 1848.

References: Dillwyn 1809, p. 43, pl. B; Lyngbye 1819, p. 184, pl. 63, fig. C; Agardh 1824, p. 8; Bory 1831, p. 102; Trevisan 1848, p. 96.

Specimen examined: stub LJH2014081022 in Sangmyung University, Seoul.

Occurrence: Melosira nummuloides was observed at BI-03, BI-04 on 12 Aug 2014 (Table 2).

Stephanopyxis palmeriana (Greville) Grunow 1884 (Fig. 5i)

Basionym: Creswellia palmeriana Greville 1865.

Synonym: Creswellia palmeriana Greville 1865.

References: Greville 1865, p. 2, pl. 1, fig. 9; Grunow 1884, p. 38.

Specimen examined: slide LJH2014080026 in Sangmyung University, Seoul.

Occurrence: Stephanopyxis palmeriana was observed at on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-04) and 12 Aug 2014 (BI-03, BI-04) (Table 2).

Stephanopyxis turris (Greville) Ralfs in Pritchard 1861 (Fig. 5j)

Basionym: Creswellia turris Greville & Arnott 1857.

Synonym: Creswellia turris Greville & Arnott 1857.

References: Greville and Arnott 1857, p. 538, pl. 14, fig. 109; Pritchard 1861, p. 826, pl. 5, fig. 74.

Specimen examined: slide LJH2014080019 in Sangmyung University, Seoul.

Occurrence: Stephanopyxis turris was observed at BI-04 on 12 Aug 2014 (Table 2).

Paralia sulcata (Ehrenberg) Cleve 1873 (Fig. 5k and 5l)

Basionym: Gaillonella sulcata Ehrenberg 1838.

Synonyms: Gaillonella sulcata Ehrenberg 1838; Melosira sulcata (Ehrenberg) Kützing 1844; Orthoseira marina W.Smith 1856; Melosira marina (Smith) Janisch 1862; Paralia marina (Smith) Heiberg 1863.

References: Ehrenberg 1838, p. 170, pl. 21, fig. 5; Kützing 1844, p. 55, pl. 2, fig. 7; Smith 1856, p. 59, pl. 53, fig. 338; Janisch 1862, p. 10, pl. 1A, figs. 3-4; Heiberg 1863, p. 33; Cleve 1873, p. 7.

Specimen examined: slide LJH2014080013 and stub LJH2015040002 in Sangmyung University, Seoul.

Occurrence: Paralia sulcata was observed at on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-05), 22 Apr 2015 (DI-01, DI-02, DI-03, SI-01) and 23 Apr 2015 (BI-03) (Table 2).

Proboscia indica (Peragallo) Hernández-Becerril 1995 (Fig. 5m)

Basionym: Rhizosolenia indica Peragallo 1892.

Synonyms: Rhizosolenia indica Peragallo 1892; Rhizosolenia alata var. indica (Peragallo) Ostenfeld in Ostenfeld & Schmidt 1901; Rhizosolenia alata f. indica (Peragallo) Gran 1908.

References: Peragallo 1892, p. 116; Ostenfeld and Schmidt 1901, p. 160; Gran 1908, p. 56; Hernández-Becerril 1995, p. 254.

Specimen examined: stub LJH2014081014 in Sangmyung University, Seoul.

Occurrence: Proboscia indica was observed at DI-03 on 11 Aug 2014 and DI-03, DI-04 on 22 Apr 2015 (Table 2).

Rhizosolenia setigera Brightwell 1858 (Fig. 5n)

References: Brightwell 1858, p. 95, pl. 5, fig. 7; Sundström 1986, p. 104, figs. 286–288; Hernández-Becerril 1995, p. 264, figs. 44, 45; Hasle and Syvertsen 1996, p. 157, pl. 30.

Specimen examined: slide LJH2014080019 in Sangmyung University, Seoul.

Occurrence: Rhizosolenia setigera was observed at DI-04 on 11 Aug 2014 and BI-04 on 12 Aug 2014 (Table 2).

Rhizosolenia setigera f. pungens (Cleve-Euler) Brunel 1962 (Fig. 5o)

Synonym: Rhizosolenia pungens Cleve-Euler 1937.

References: Cleve-Euler 1937, 43, fig. 10; Brunel 1962, p. 66, pl. 4, figs. 5, 6; Hernández-Becerril 1995, p. 264, figs. 36–40; Hasle and Syvertsen 1996, p. 157, pl. 30; Sar 1996, p. 381.

Specimen examined: stub LJH2014081005 in Sangmyung University, Seoul.

Occurrence: Rhizosolenia setigera f. pungens was observed on 11 Aug.2014 (BI-02, DI-01, DI-02, DI-03, DI-04) and 12 Aug 2014 (BI-03) (Table 2).

Trigonium alternans (Bailey) Mann 1907 (Fig. 5p and 5q)

Basionym: Triceratium alternans Bailey 1851.

Synonyms: Triceratium alternans Bailey 1851; Biddulphia alternans (Bailey) Van Heurck 1885.

References: Bailey 1851, p. 40; Van Heurck 1885, p. 208; Mann 1907, p. 290.

Specimen examined: slide LJH2014080020 and stub LJH2014081028 in Sangmyung University, Seoul.

Occurrence: Trigonium alternans was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-04, BI-05) and 22 Apr 2015 (DI-02) (Table 2).

Cerataulina dentata Hasle 1980 (Fig. 5r and 5s)

References: Hasle and Syvertsen 1980, p. 87, figs. 65, 72-94, 97; Hasle and Syvertsen 1996, pl. 33, figs. a-c.

Specimen examined: slide LJH2014080030 in Sangmyung University, Seoul.

Occurrence: Cerataulina dentata was observed at DI-01 on 11 Aug 2014 and BI-03, BI-04 on 12 Aug 2014 (Table 2).

Eucampia zodiacus Ehrenberg 1839 (Fig. 6a and 6b)

Fig. 6.Light microscopy (a, f, h, j, l, n) and scanning electron microscopy (b-e, g, i, k, m, o) microphotographs. (a, b) Eucampia zodiacus. (c) Odontella aurita. (d) Odontella longicruris. (e) Triceratium dubium. (f) Triceratium favus. (g) Trieres mobiliensis. (h) Trieres sinensis. (i) Bacteriastrum hyalinum. (j) Chaetoceros affinis. (k) Chaetoceros concavicornis. (l) Chaetoceros contortus. (m, n) Chaetoceros curvisetus. (o) Chaetoceros danicus. Scale bars represent: a, d-h, j-l, n, o, 10 μm; b, c, m, 5 μm; i, 50 μm.

Synonyms: Eucampia britannica Smith 1853; Eucampia nodosa Schmidt 1888.

References: Ehrenberg 1839, p. 156; Smith 1856, p. 25, pl. 61, fig. 378; Schmidt 1888, pl. 141, fig. 28.

Specimen examined: slide LJH2014080003 and stub LJH2015041027 in Sangmyung University, Seoul.

Occurrence: Eucampia zodiacus was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03) and 23 Apr 2015 (BI-02, BI-05) (Table 2).

Odontella aurita (Lyngbye) Agardh 1832 (Fig. 6c)

Basionym: Diatoma aurita Lyngbye 1819.

Synonyms: Diatoma aurita Lyngbye 1819; Biddulphia aurita (Lyngbye) Brébisson 1838.

References: Lyngbye 1819, p. 182, pl. 62, fig. D; Agardh 1832, p. 56; Brébisson 1838, p. 12.

Specimen examined: stub LJH2014081007 in Sangmyung University, Seoul.

Occurrence: Odontella aurita was observed at BI-02 on 11 Aug. 2014 and BI-05 on 12 Aug. 2014 (Table 2).

Odontella longicruris (Greville) Hoban 1983 (Fig. 6d)

Basionym: Biddulphia longicruris Greville 1859.

Synonyms: Biddulphia longicruris Greville 1859; Biddulphia longicruris var. hyalina (Schröder) Cupp 1943.

References: Greville 1859, p. 163, pl. 8, fig. 10; Cupp 1943, pp 157-161, fig. 111; Hoban 1983, p. 283.

Specimen examined: stub LJH2014080018 in Sangmyung University, Seoul.

Occurrence: Odontella longicruris was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-04, BI-05), 22 Apr 2015 (DI-01, DI-02, DI-04), 11 Aug 2014 (BI-01) and 23 Apr 2015 (BI-05) (Table 2).

Triceratium dubium Brightwell 1859 (Fig. 6e)

Synonyms: Biddulphia dubia (Brightwell) Cleve 1883; Biddulphia reticulata var. dubia (Brightwell) Cleve 1883; Odontella dubia (Brightwell) Cleve 1901; Odontella dubia (Brightwell) Chavez & Baumgartner 1983.

References: Brightwell 1859, p. 180; pl. 9, fig. 12; Cleve 1883, pp 503, 508; Cleve 1901, p. 31; Chavez and Baumgartner 1983, p. 68, figs. 2, 3, 9, 10, 11.

Specimen examined: stub LJH2014081028 in Sangmyung University, Seoul.

Occurrence: Triceratium dubium was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03), 22 Apr 2015 (DI-02) and 23 Apr 2015 (BI-03) (Table 2).

Triceratium favus Ehrenberg 1840 (Fig. 6f)

Synonyms: Biddulphia favus (Ehrenberg) Van Heurck 1885; Odontella favus (Ehrenberg) Cleve 1901; Odontella favus (Ehrenberg) Peragallo 1903.

References: Ehrenberg 1840, p. 79, pl. 4, fig. 10; Van Heurck 1885, p. 208; Cleve 1901, p. 31; Peragallo 1903, p. 687.

Specimen examined: slide LJH2014080004 in Sangmyung University, Seoul.

Occurrence: Triceratium favus was observed on 11 Aug 2014 (BI-01, DI-01, DI-02, DI-03, DI-04, SI-01) and 22 Apr 2015 (DI-01) (Table 2).

Trieres mobiliensis (Bailey) Ashworth & Theriot 2013 (Fig. 6g)

Basionym: Zygoceros mobiliensis Bailey 1851.

Synonyms: Zygoceros mobiliensis Bailey 1851; Biddulphia mobiliensis (Bailey) Grunow 1882; Odontella mobiliensis (Bailey) Grunow 1884; Denticella mobiliensis (Bailey) Grunow 1884.

References: Bailey 1851, p. 40, pl. 2, figs. 34-35; Grunow 1882, pl. 101, figs. 4-6; Grunow 1884, pp 6, 58; Ashworth et al. 2013, p. 1220, 1221.

Specimen examined: stub LJH2014081006 in Sangmyung University, Seoul.

Occurrence: Trieres mobiliensis was observed at DI-03, BI-01, BI-02 on 11 Aug 2014 (Table 2).

Trieres sinensis (Greville) Ashworth & Theriot 2013 (Fig. 6h)

Basionym: Biddulphia sinensis Greville 1866.

Synonyms: Biddulphia sinensis Greville 1866; Odontella sinensis (Greville) Grunow 1884.

References: Greville 1866, p. 81, pl. 9, fig. 16; Grunow 1884, p. 58; Ashworth et al. 2013, p. 16

Specimen examined: slide LJH2014080027 in Sangmyung University, Seoul.

Occurrence: Trieres sinensis was observed on 11 Aug 2014 (BI-01, DI-01, DI-02, DI-03, DI-04) and 12 Aug 2014 (BI-04) (Table 2).

Bacteriastrum hyalinum Lauder 1864 (Fig. 6i)

Synonyms: Bacteriastrum varians var. hyalina (Lauder) Peragallo & Peragallo 1897-1908; Bacteriastrum varians f. hyalina (Lauder) Frenguelli 1928.

References: Lauder 1864, p. 8, pl. 3, fig. 7; Peragallo and Peragallo 1897-1908, p. 470; Frenguelli 1928, p. 543.

Specimen examined: stub LJH2014081019 in Sangmyung University, Seoul.

Occurrence: Bacteriastrum hyalinum was observed at BI-04 on 12 Aug 2014 (Table 2).

Chaetoceros affinis Lauder 1864 (Fig. 6j)

Synonyms: Chaetoceros javanicus Cleve 1873; Chaetoceros ralfsii Cleve 1873; Chaetoceros angulatus Schütt 1895.

References: Lauder 1864, p. 78, pl. 8, fig. 5; Cleve 1873, p. 10, pl. 2, fig. 13, pl. 3, fig. 15; Schütt 1895, p. 37, fig. 1.

Specimen examined: slide LJH2014080022 in Sangmyung University, Seoul.

Occurrence: Chaetoceros affinis was observed at DI-04 on 11 Aug 2014 and BI-03, BI-04 on 12 Aug 2014 (Table 2).

Chaetoceros concavicornis Mangin 1917 (Fig. 6k)

Synonym: Chaetoceros borealis f. concavicornis (Mangin) Braarud 1935.

References: Mangin 1917, p. 9, figs. 5-7; Braarud 1935, p. 92.

Specimen examined: stub LJH20140810019 in Sangmyung University, Seoul.

Occurrence: Chaetoceros concavicornis was observed at BI-04 on 12 Aug 2014 (Table 2).

Chaetoceros contortus Schütt 1895 (Fig. 6l)

References: Schütt 1895, p. 44.

Specimen examined: slide LJH2014080019 in Sangmyung University, Seoul.

Occurrence: Chaetoceros contortus was observed on 11 Aug 2014 (BI-01, DI-01, DI-02, DI-04) and 12 Aug 2014 (BI-03, BI-04) (Table 2).

Chaetoceros curvisetus Cleve 1889 (Fig. 6m and 6n)

References: Cleve 1889, p. 55.

Specimen examined: stub LJH2014081029 and slide LJH2014080026 in Sangmyung University, Seoul.

Occurrence: Chaetoceros curvisetus was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04) and 12 Aug 2014 (BI-03, BI-04) (Table 2).

Chaetoceros danicus Cleve 1889 (Fig. 6o)

References: Cleve 1889, p. 55.

Specimen examined: stub LJH2014081023 in Sangmyung University, Seoul.

Occurrence: Chaetoceros danicus was observed at BI-03 and BI-04 on 12 Aug 2014 (Table 2).

Chaetoceros debilis Cleve 1894 (Fig. 7a)

Fig. 7.Light microscopy (a-f, i, l) and scanning electron microscopy (g, h, j, k, m) microphotographs. (a) Chaetoceros debilis. (b) Chaetoceros decipiens. (c) Chaetoceros didymus. (d) Chaetoceros laciniosus. (e) Chaetoceros lorenzianus. (f ) Chaetoceros protuberans. (g) Chaetoceros radicans. (h) Chaetoceros similis. (i) Chaetoceros socialis. (j, k) Cymatosira belgica. (l, m) Plagiogrammopsis vanheurckii. Scale bars represent: a-g, i, l, 10 μm; h, 20 μm, m, 5 μm, j, k, 2 μm.

Synonym: Chaetoceros vermiculatus Schütt 1895.

References: Cleve 1894, p. 13, pl. 1, fig. 2; Schütt 1895, p. 39, fig. 7.

Specimen examined: slide LJH2015040023 in Sangmyung University, Seoul.

Occurrence: Chaetoceros debilis was observed at DI-03 on 11 Aug 2014, BI-04 on 12 Aug 2014 and SI-01 on 22 Apr. 2015 (Table 2).

Chaetoceros decipiens Cleve 1873 (Fig. 7b)

Synonyms: Chaetoceros decipiens var. grunowii (F.Schütt) Cleve 1897; Chaetoceros grunowii F.Schütt 1895.

References: Cleve 1873, p. 11, pl. 1, fig. 5a, 5b; Cleve 1897, p. 21; Schütt 1895, p. 43, pl. 4, fig. 14.

Specimen examined: slide LJH2014080023 in Sangmyung University, Seoul.

Occurrence: Chaetoceros decipiens was observed at BI-03 on 12 Aug 2014 (Table 2).

Chaetoceros didymus Ehrenberg 1845 (Fig. 7c)

References: Ehrenberg 1845, p. 75.

Specimen examined: slide LJH2014080030 in Sangmyung University, Seoul.

Occurrence: Chaetoceros didymus was observed at DI-01, BI-01 on 11 Aug 2014 and BI-04 on 12 Aug 2014 (Table 2).

Chaetoceros laciniosus Schütt 1895 (Fig. 7d)

References: Schütt 1895, p. 38, pl. 4, fig. 5.

Specimen examined: slide LJH2014080022 in Sangmyung University, Seoul.

Occurrence: Chaetoceros laciniosus was observed at BI-04 on 12 Aug. 2014 (Table 2).

Chaetoceros lorenzianus Grunow 1863 (Fig. 7e)

Synonym: Chaetoceros cellulosus Lauder 1864.

References: Grunow 1863, p. 157, pl. 5, fig. 13; Lauder 1864, p. 78, pl. 8, fig. 12.

Specimen examined: slide LJH2014080030 in Sangmyung University, Seoul.

Occurrence: Chaetoceros lorenzianus was observed on 11 Aug 2014 (BI-02, DI-01, DI-02, DI-03, DI-04), 12 Aug 2014 (BI-03) and 23 Apr 2015 (BI-05) (Table 2).

Chaetoceros protuberans Lauder 1864 (Fig. 7f)

Synonym: Chaetoceros didymus var. protuberans (Lauder) Gran & Yendo 1914.

References: Lauder 1864, p. 79, pl. 8, fig. 11; Gran and Yendo 1914, p. 72, fig. 5.

Specimen examined: slide LJH2014080022 in Sangmyung University, Seoul.

Occurrence: Chaetoceros protuberans was observed at BI-04 on 12 Aug 2014 (Table 2).

Chaetoceros radicans Schütt 1895 (Fig. 7g)

Synonym: Chaetoceros scolopendra Cleve 1896.

References: Schütt 1895, p. 48, pl. 5, fig. 27; Cleve 1896, p. 30, figs. 4-6.

Specimen examined: stub LJH2015041018 in Sangmyung University, Seoul.

Occurrence: Chaetoceros radicans was observed at BI-04 on 12 Aug 2014 and SI-01 on 22 Apr 2015 (Table 2).

Chaetoceros similis Cleve 1896 (Fig. 7h)

References: Cleve 1896, p. 30, pl. 1, fig. 1.

Specimen examined: stub LJH2015041010 in Sangmyung University, Seoul.

Occurrence: Chaetoceros similis was observed at BI-05 on 23 Apr 2015 (Table 2).

Chaetoceros socialis Lauder 1864 (Fig. 7i)

Synonyms: Chaetoceros radians Schütt 1895; Chaetoceros socialis f. autumnalis Proshkina-Lavrenko 1953; Chaetoceros socialis f. vernalis Proshkina-Lavrenko 1953; Chaetoceros socialis f. radians (Schütt) Proshkina-Lavrenko 1963; Chaetoceros socialis var. radians (Schutt) Tsarenko 2009

References: Schütt 1895, p. 41, pl. 4, fig. 10a, pl. 5, fig. 10b, d; Proschkina-Lavrenko 1953, p. 51, fig. 38; Proschkina-Lavrenko 1953, p. 51, figs. 3f-j; Proschkina-Lavrenko 1963, p. 113, pl. 21, figs. 8-15; Lauder 1864, p. 77, pl. 8, fig. 1; Tsarenko et al. 2009, p. 42.

Specimen examined: slide LJH2014080022 in Sangmyung University, Seoul.

Occurrence: Chaetoceros socialis was observed at BI-04 on 12 Aug 2014 (Table 2).

Cymatosira belgica Grunow in Van Heurck 1881 (Fig. 7j and 7k)

References: Van Heurck 1881, p. pl. 45, figs. 38-41.

Specimen examined: stub LJH2014081013 in Sangmyung University, Seoul.

Occurrence: Cymatosira belgica was observed on 11 Aug 2014 (BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-05), 22 Apr 2015 (DI-01, DI-02) and 23 Apr 2015 (BI-01, BI-04) (Table 2).

Plagiogrammopsis vanheurckii (Grunow) Hasle, von Stosch & Syvertsen 1983 (Fig. 7l and 7m)

Basionym: Plagiogramma vanheurckii Grunow in Van Heurck 1881.

Synonym: Plagiogramma vanheurckii Grunow in Van Heurck 1881.

References: Van Heurck 1881, p. 145, pl. 36, fig. 4; Hasle

Specimen examined: slide LJH2014080006 and stub LJH2014081012 in Sangmyung University, Seoul.

Occurrence: Plagiogrammopsis vanheurckii was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-05), 22 Apr 2015 (DI-01, DI-03) and 23 Apr 2015 (BI-04, BI-05) (Table 2).

Ditylum brightwellii (West) Grunow in Van Heurck 1885 (Fig. 8a)

Fig. 8.Light microscopy (c, e, f, h) and scanning electron microscopy (a, b, d, g, h, i-p) microphotographs. (a) Ditylum brightwellii. (b) Detonula pumila. (c, d) Cyclotella litoralis. (e) Cymatotheca weissflogii. (f ) Planktoniella blanda. (g) Porosira pentaportula. (h) Shionodiscus poroirregulatus. (i) Thalassiosira allenii. (j) Thalassiosira anguste-lineata. (k) Thalassiosira binate. (l) Thalassiosira constricta. (m) Thalassiosira curviseriata. (n) Thalassiosira decipiens. (o, p) Thalassiosira eccentrica. Scale bars represent: a, c-h, o, p, 10 μm; b, i, j, 5 μm; k-n, 2 μm.

Basionym: Triceratium brightwellii West 1860.

Synonyms: Triceratium brightwellii West 1860; Ditylum trigonum Bailey ex Bailey 1862; Ditylum inaequale Bailey ex Bailey 1862.

References: West 1860, p. 149, pl. 7, fig. 6; Bailey 1862, p. 332, pl. 7, figs. 6, 10, 11, p. 332, pl. 7, figs 12-14; Van Heurck 1885, p. 196, pl. 114, figs. 3-9.

Specimen examined: stub LJH2014081014 in Sangmyung University, Seoul.

Occurrence: Ditylum brightwellii was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-04), and 23 Apr 2015 (BI-05) (Table 2).

Detonula pumila (Castracane) Gran 1900 (Fig. 8b)

Basionym: Lauderia pumila Castracane 1886.

Synonyms: Lauderia pumila Castracane 1886; Lauderia delicatula Peragallo 1888; Thalassiosira condensata Cleve 1900; Lauderia schroederi Bergon 1903; Schroederella delicatula (Peragallo) Pavillard 1913; Schroederella schroederi (Bergon) Pavillard 1925.

References: Castracane 1886, p. 89, pl. 9, fig. 8; Peragallo 1888, p. 81, pl. 6, fig. 46; Cleve 1900, p. 22, pl. 8, figs 12, 13; Gran 1900, p. 113; Bergon 1903, p. 69; Pavillard 1913, p. 126; Pavillard 1925, p. 23, fig. 33.

Specimen examined: stub LJH2014081008 in Sangmyung University, Seoul.

Occurrence: Detonula pumila was observed at BI-03 and BI-04 on 12 Aug 2014 (Table 2).

Cyclotella litoralis Lange & Syvertsen 1989 (Fig. 8c and 8d)

References: Lange and Syvertsen 1989, pp 343-344, figs. 1-30.

Specimen examined: slide LJH2014080003 and stub LJH2015041019 in Sangmyung University, Seoul.

Occurrence: Cyclotella litoralis was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03), 22 Apr 2015 (DI-02), and 23 Apr 2015 (BI-03, BI-05) (Table 2).

Cymatotheca weissflogii (Grunow) Hendey 1958 (Fig. 8e)

Basionym: Euodia weissflogii Grunow in Van Heurck 1883.

Synonyms: Euodia weissflogii Grunow in Van Heurck 1882; Hemidiscus weissflogii (Grunow) Kuntze 1898; Hemidiscus weissflogi (Grunow in Van Heurck) Hustedt 1955.

References: Van Heurck 1882, pl. 126, fig. 13; Kuntze 1898, p. 408; Hustedt 1955, p. 11, pl. 1, fig. 6; Hendey 1958, p. 41, pl. 5, fig. 9; Tremarin et al. 2008, p. 1103, figs. 3-4, 61; Lehmkuhl et al. 2010, p. 319, fig. 25.

Specimen examined: slide LJH2014080008 in Sangmyung University, Seoul.

Occurrence: Cymatotheca weissflogii was observed at DI-01 on 11 Aug 2014 and BI-03 on 12 Aug 2014 (Table 2).

Planktoniella blanda (Schmidt) Syvertsen & Hasle 1993 (Fig. 8f)

Basionym: Coscinodiscus blandus Schmidt 1878.

Synonyms: Coscinodiscus blandus Schmidt 1878; Thalassiosira blandus (Schmidt) Desikachary and Gowthaman 1989.

References: Schmidt 1878, pl. 59, figs. 35-37; Desikachary 1989, pl. 742, figs. 1-7, pl. 743, figs. 1-5, pl. 744, figs. 1-5; Hasle 1993, p. 304, figs. 19-31; Hasle and Syvertsen 1996, p. 40, pl. 2.

Specimen examined: slide LJH2014080018 in Sangmyung University, Seoul.

Occurrence: Planktoniella blanda was observed at DI-02 on 11 Aug 2014 and BI-03 on 12 Aug 2014 (Table 2).

Porosira pentaportula Syvertsen & Lange 1990 (Fig. 8g)

References: Syvertsen and Lange, 1990, p. 144, figs. 1-21.

Specimen examined: stub LJH2015041003 in Sangmyung University, Seoul.

Occurrence: Porosira pentaportula was observed at DI-03 and SI-01 on 22 Apr 2015 (Table 2).

Shionodiscus poroirregulatus (Hasle & Heimdal) Alverson, Kang & Theriot 2006 (Fig. 8h)

Basionym: Thalassiosira poro-irregulata Hasle & Heimdal 1970.

Synonym: Thalassiosira poro-irregulata Hasle & Heimdal 1970.

References: Hasle and Heimdal 1970, p. 573, pl. 10, figs. 55-60, pl. 11, figs. 61-64, pl. 13, figs. 71, 72; Alverson et al. 2006, p. 260.

Specimen examined: stub LJH2014081018 in Sangmyung University, Seoul.

Occurrence: Shionodiscus poro-irregulatus was observed on 11 Aug 2014 (BI-01, BI-02, DI-02, SI-01), 12 Aug 2014 (BI-03) (Table 2).

Thalassiosira allenii Takano 1965 (Fig. 8i)

References: Takano 1965, p. 4, pl. 1, figs. 9-11, pl. 2, fig. 1.

Specimen examined: stub LJH2015041014 in Sangmyung University, Seoul.

Occurrence: Thalassiosira allenii was observed at BI-02 on 23 Apr 2015 (Table 2).

Thalassiosira anguste-lineata (Schmidt) Fryxell & Hasle 1977 (Fig. 8j)

Basionym: Coscinodiscus anguste-lineatus Schmidt 1878.

Synonyms: Coscinodiscus anguste-lineatus Schmidt 1878; Coscinodiscus polychordus Gran 1897; Thalassiosira polychorda (Gran) Jorgensen 1899; Coscinosira polychorda (Gran) Gran 1900.

References: Gran 1897, p. 30, pl. 2, fig. 33; Schmidt 1878, pl. 59, fig. 34; Jørgensen 1899, p. 15; Gran 1900, p. 115; Fryxell and Hasle 1977, p. 73, figs. 22-34.

Specimen examined: stub LJH2014081021 in Sangmyung University, Seoul.

Occurrence: Thalassiosira anguste-lineata was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, SI-01), 12 Aug 2014 (BI-03, BI-04), 22 Apr 2015 (DI-04) and 23 Apr 2015 (BI-05) (Table 2).

Thalassiosira binata Fryxell 1977 (Fig. 8k)

References: Fryxell 1977, p. 244, figs. 24-38.

Specimen examined: stub LJH2014081015 in Sangmyung University, Seoul.

Occurrence: Thalassiosira binata was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-04, SI-01) (Table 2).

Thalassiosira constricta Gaarder 1938 (Fig. 8l)

References: Gaarder 1938, p. 6, fig. 6.

Specimen examined: stub LJH2015041018 in Sangmyung University, Seoul.

Occurrence: Thalassiosira constricta was observed at SI-01 on 22 Apr 2015 and BI-03 23 Apr 2015 (Table 2).

Thalassiosira curviseriata Takano 1981 (Fig. 8m)

References: Takano 1981, p. 34, figs. 1C, 26-28.

Specimen examined: stub LJH2015041001 in Sangmyung University, Seoul.

Occurrence: Thalassiosira curviseriata was observed on 22 Apr 2015 (DI-01, DI-02, DI-04, SI-01), 23 Apr 2015 (BI-01, BI-02, BI-03, BI-04) (Table 2).

Thalassiosira decipiens (Grunow) Jørgensen 1905 (Fig. 8n)

Basionym: Coscinodiscus eccentricus var. decipiens Grunow 1878.

Synonyms: Coscinodiscus eccentricus var. decipiens Grunow 1878; Coscinodiscus decipiens Grunow ex Van Heurck 1882.

References: Grunow 1878, p. 125, pl. 4, fig. 18; Van Heurck 1882, pl. 91, fig. 10; Jørgensen 1905, p. 96, pl. 6, fig. 3.

Specimen examined: stub LJH2014081027 in Sangmyung University, Seoul.

Occurrence: Thalassiosira decipiens was observed on 11 Aug 2014 (BI-01, BI-02, DI-02, DI-03, DI-04), 22 Apr 2015 (DI-01, DI-02) and 23 Apr 2015 (BI-05) (Table 2).

Thalassiosira eccentrica (Ehrenberg) Cleve 1904 (Fig. 8o and 8p)

Basionym: Coscinodiscus eccentricus Ehrenberg 1840.

Synonyms: Coscinodiscus eccentricus Ehrenberg 1840; Thalassiosira excentrica (Ehrenberg) Cleve 1904; Thalassiosira kryophila (Grunow) Jørgensen 1905.

References: Ehrenberg 1840, p. 146; Cleve 1904, p. 216; Jørgensen 1905, p. 96, pl. 6, fig. 6.

Specimen examined: stub LJH2014081030 in Sangmyung University, Seoul.

Occurrence: Thalassiosira eccentrica was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-04, BI-05), 22 Apr 2015 (DI-02, DI-03, DI-04, SI-01) and 23 Apr 2015 (BI-03, BI-05) (Table 2).

Thalassiosira gravida Cleve 1896 (Fig. 9a and b)

Fig. 9.Light microscopy (c, e, g, i, j) and scanning electron microscopy (a, b, d, f, h, k, l) microphotographs. (a, b) Thalassiosira gravida. (c) Thalassiosira lundiana. (d) Thalassiosira mala. (e, f ) Thalassiosira minicosmica. (g, h) Thalassiosira nordenskioeldii. (i) Thalassiosira punctigera. (j-l) Thalassiosira tenera. Scale bars represent: a, c, e-g, i, j, 10 μm; b, d, l, 1 μm; h, k, 5 μm.

Synonyms: Thalassiosira rotula Meunier 1910; Coscinodiscus rotulus (Meunier) Cleve-Euler 1951; Thalassiosira tcherniai Manguin 1954 Coscinodiscus pelagicus Woodhead & Tweed 1960.

References: Cleve 1896, p. 12, pl. 2, figs. 14-16; Meunier 1910, p. 264, pl. 29, figs. 67-70; Cleve-Euler 1951, p. 74; Manguin 1954, p. 115, figs. 9, 51; Woodhead and Tweed 1960, p. 239.

Specimen examined: stub LJH2015041009 in Sangmyung University, Seoul.

Occurrence: Thalassiosira gravida was observed at BI-03 on 12 Aug 2014 and BI-02, BI-04 on 23 Apr 2015 (Table 2).

Thalassiosira lundiana Fryxell 1975 (Fig. 9c)

References: Fryxell 1975, p. 64, pls. 3, 4.

Specimen examined: slide LJH2014080023 in Sangmyung University, Seoul.

Occurrence: Thalassiosira lundiana was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-03, SI-01) and 12 Aug 2014 (BI-03, BI-04) (Table 2).

Thalassiosira mala Takano 1965 (Fig. 9d)

References: Takano 1965, p. 1, fig. 1a-m, pl. 1, figs. 1-8.

Specimen examined: stub LJH2015041025 in Sangmyung University, Seoul.

Occurrence: Thalassiosira mala was observed on 22 Apr 2015 (DI-01, DI-02, DI-03, DI-04, SI-01), 23 Apr 2015 (BI-01, BI-02, BI-03) (Table 2).

Thalassiosira minicosmica Park & Lee 2015 (Fig. 9e and 9f)

References: Park and Lee 2015, p. 164, figs. 1-33.

Specimen examined: slide LJH2014080024 and stub LJH2015041013 in Sangmyung University, Seoul.

Occurrence: Thalassiosira minicosmica was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04), 12 Aug 2014 (BI-03) and 23 Apr 2015 (BI-03) (Table 2).

Thalassiosira nordenskioeldii Cleve 1873 (Fig. 9g and 9h)

Synonym: Coscinodiscus nordenskioldii (Cleve) Cleve-Euler 1951.

References: Cleve 1873, p. 7, pl. 1, fig. 1; Cleve-Euler 1951, p. 71.

Specimen examined: slide LJH2014080026 and stub LJH2015041002 in Sangmyung University, Seoul.

Occurrence: Thalassiosira nordenskioeldii was observed at DI-01, DI-03, DI-04 on 11 Aug 2014 and DI-01, DI-02 on 22 Apr 2015 (Table 2).

Thalassiosira punctigera (Castracane) Hasle 1983 (Fig. 9i)

Basionym: Ethmodiscus punctiger Castracane 1886.

Synonyms: Ethmodiscus punctiger Castracane 1886; Coscinodiscus angstii Gran 1931.

References: Castracane 1886, p. 167, pl. 3, fig. 1; Gran and Angst 1931, p. 443, fig. 19; Hasle 1983, p. 602.

Specimen examined: slide LJH2014080008 in Sangmyung University, Seoul.

Occurrence: Thalassiosira punctigera was observed on 11 Aug 2014 (BI-01, BI-02, DI-01, DI-02, DI-03, DI-04, SI-01), 12 Aug 2014 (BI-03) (Table 2).

Thalassiosira tenera Proschkina-Lavrenko 1961 (Fig. 9j-9l)

References: Proschkina-Lavrenko 1961, p. 33, pl. 1, figs. 1-4, pl. 2, figs. 5-7.

Specimen examined: slide LJH2014080028 and stub LJH2015041020 in Sangmyung University, Seoul.

Occurrence: Thalassiosira tenera was observed on 11 Aug 2014 (DI-01, DI-02, DI-04, SI-01), 12 Aug 2014 (BI-03, BI-04, BI-05), 22 Apr 2015 (DI-01) and 23 Apr 2015 (BI-03) (Table 2).

 

CONCLUSION

One hundred seventeen diatom species representing 3 classes, 9 subclasses, 20 orders, 32 families and 54 genera were investigated from 10 stations of Baeknyeong, Daecheong, and Socheong Islands in Yellow Sea of Korea. Three species, Gyrosigma obscurum, Pleurosigma frenguellianum, Pleurosigma sabangi, were newly recorded in Korea. We presented the distribution of the diatom species in this study. One hundred seven species were identified in the Baeknyeong Island, 70 diatom species were found in the Daecheong Island and 38 species were found from the Socheong Island (Table 2). Diatom species diversity and frequency were similar to among the stations (DI-01 to DI-04) in Daecheong Isalnd, but Baeknyeong Island, 75 taxa were found in BI-03 while 23 species were found in BI-05. All newly recorded species were found in the Baeknyeong Island (Table 2).

The most species rich genus were Chaetoceros and Thalassiosira, 14 taxa were found respectively. Chaetoceros have been known to the representatively planktonic diatom and the most species-rich genera in the marine or brackish water (Hernández-Becerril 1995, Hasle and Syvertsen 1996, Lee et al. 2014a, 2014b). In Korea, 56 Chaetoceros species have been described and published from the Yellow Sea, the East Sea and the South Sea (Lee and Lee 2011, 2014, Lee et al. 2014a, 2014b), and 40 Thalassiosira taxa were reported (Park and Lee 2010, Lee et al. 2012).

The most frequent species were Cymatosira belagica (10 sites), Ditylum brightwellii (10 sites), Odontella longicruris (10 sites), Plagiogrammopsis vanheurckii (10 sites), Thalassiosira eccentrica (10 sites), Trigonium alternans (10 sites), Actinocyclus octonarius var. ralfsii (9 sites), Actinoptychus senarius (9 sites), Coscinodiscus radiatus (9 sites), Eucampia zodiacus (9 sites), Paralia sulcata (9 sites), Pleurosigma aestuarii (9 sites) from 10 stations of three Islands (Table 2). Cymatosira belagica and Plagiogrammopsis vanheurckii have been known to marine benthic diatom, and Paralia sulcata have been known to the epipelic species in the marine sediments (Round et al. 1990). Fourty species were found once in 10 stations as follows: Achnanthes subconstricta, Actinocyclus normanii, Halaphora coffeiformis, Bacteriastrum hyalinum, Carinasigma rectum, Chaetoceros concavicornis, Chaetoceros decipiens, Chaetoceros laciniosus, Chaetoceros protuberans, Chaetoceros similis, Chaetoceros socialis, Cocconeis pseudomarginata, Cocconeis scutellum, Cocconeis stauroneiformis, Coscinodiscopsis jonesianus, Cymbella aspera, Delphineis minutissima, Dipoloneis weissflogii, Gyrosigma fasciola, Gyrosigma littorale, Gyrosigma obscurum, Hyalodiscus scoticus, Licmophora flabellate, Navicula directa, Navicula gregaria, Nitzschia bilobata, Nitzschia valdestriata, Parlibellus berkeleyi, Parlibellus rhombiformis, Petrodictyon gemmoides, Planothidium septentrionalis, Pleurosigma amara, Pleurosigma angulatum, Pleurosigma frenguellianum, Pleurosigma inflatum, Pleurosigma sabangi, Stephanophyxis turris, Tabularia fasciculata, Thalassiosira allenii, and Thalassiosira onstricta.

Diatom flora and newly recorded taxa have not reported and published from Baeknyeong, Daecheong, and Socheong Islands in Yellow Sea of Korea. This study contributes to the understanding of diatom flora and diversity of Korea. Further in-depth taxonomic and floristic studies should be examined in various regions of marine, brackish and fresh water in Korea.