• ALGAE
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• 제36권2호
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• pp.91-109
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• 2021

The occurrence of benthic dinoflagellates, many of which are known to be toxic, is a critical concern for scientists, government officers, and people in the aquaculture, dining, and tourism industries. The interest in these dinoflagellates in countries with temperate climate is increasing because tropical or subtropical species introduced into temperate waters by currents are able to survive the winter season in the new environment owing to global warming. Recently, several species from the benthic dinoflagellate genera Amphidinium, Coolia, Ostreopsis, Gambierdiscus, and Prorocentrum have been reported in the waters of the South and East Sea of Korea. The advent of the benthic dinoflagellates in Korean waters is especially important because raw or slightly cooked seaweeds, which may harbor these benthic dinoflagellates, as well as raw fish, which can be potentially intoxicated by phytotoxins produced by some of these benthic dinoflagellates, are part of the daily Korean diet. The recent increase in temperature of Korean coastal waters has allowed for the expansion of benthic dinoflagellate species into these regions. In the present study, we reviewed the species, distribution, and toxicity of the benthic dinoflagellates that have been reported in Korean waters. We also provided an insight into the ecological and socio-economic importance of the occurrence of benthic dinoflagellates in Korean waters.

• Journal of Ecology and Environment
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• 제36권4호
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• pp.347-370
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• 2013

A study on the presence of benthic dinoflagellates in the intertidal zone along the coasts of Jeju Island, Korea was conducted during 2011 and 2012. Identification and taxonomic observations were made of the benthic dinoflagellate samples using light and epifluorescence microscopy. Thirty-seven dinoflagellate taxa belong to five orders, nine families, 18 genera and 30 species, which are new records for Korean waters, were detected in this study. The detailed nomenclature, references, distribution, and illustrations are presented here. The commonly occurring genera were Amphidinium, Coolia, Ostreopsis, Prorocentrum, and Thecadinium. Among the recorded species, 26 were found only in sand sediment, seven in macroalgal samples, and four were found in both sand and macroalgal samples. Of the 37 species, nine were potentially toxic. These results suggest that diversified benthic dinoflagellates including several potentially toxic species occur in sand sediment and macroalgae in the intertidal zone along the coasts of Jeju Island. The morphological features of the identified species were more or less similar to observations made by previous studies in Korea and elsewhere. The presence of known toxic species may indicate a potential risk of toxicity in the marine ecosystem of Jeju Island. The present study can be helpful for further detailed taxonomic, toxicological, molecular phylogenetic studies and may help in the management and conservation of Jeju Island's marine ecosystem.

• 환경생물
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• 제36권3호
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• pp.252-259
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• 2018

A research probing for the unrecorded and taxonomically undescribed indigenous species has been initiated since 2006. Samples were collected from an intertidal zone along the coasts of Korea as well as around the Jeju Island. We have found five unrecorded species of four genera belonging to the order Dinophysiales, Gymnodiniales, Peridiniales, and Prorocentrales. The species are as follows, Sinophysis canaliculata (2017) Bispidodinium angelaceum (2015), Cabra armorica (2016), Prorocentrum bimaculatum (2017), and P. tsawwassenense (2017) (note; The numbers in parenthesis refer to the year in which the species was reported as unrecorded indigenous species by National Institute of Biological Resources, NIBR hereafter).

• ALGAE
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• 제30권4호
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• pp.325-326
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• 2015

• 한국해양학회지:바다
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• 제20권3호
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• pp.141-150
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• 2015

와편모류는 해양의 주요 일차 생산자로서, 독립영양성, 종속영양성 및 혼합영양성 등의 다양한 영양방식을 가지는 생물군으로서 해양 미소먹이망에서 중요한 생태학적 역할을 담당하고 있다. 그러나 와편모류에 대한 대부분의 연구가 연안이나 외해의 표영생태계에 국한되어 수행되었으며, 사질조간대에 서식하는 저서성 와편모류에 대한 연구는 매우 미흡하며, 국내에서는 제주연안을 제외하고는 거의 전무하다. 본 연구는 전라북도 서해안에 위치한 동호의 사질조간대에서 2012년 11월부터 2014년 2월까지 매월 간조기에 저서성 와편모류의 출현양상을 조사하고 주요 출현종의 28S rDNA 염기서열을 획득하여 분자계통학적 분석을 실시하였다. 연구기간동안 Gymnodiniales, Gonyaulacales, Peridiniales, Prorocentrales의 4개 목에 속하는 총 13속 27종의 저서성 와편모류가 출현하였고, Amphidinium 속이 9종으로 가장 다양한 종이 출현하였다. 동호를 비롯하여 서해안에 위치한 모항, 송호, 가마미와 제주 협재에서 분리한 저서성 와편모류 총 16종, 34개 종주에서 28S rDNA 염기서열 정보를 성공적으로 확보하였으며, 분자계통학적 분석에 이용하였다. Amphidinium에 속하는 종들은 Gymodiniales 목의 4개의 분기군 가운데 3개의 분기군에 걸쳐서 분지하여, 다계통학적(polyphyletic) 특성을 나타내었다. 28S rDNA염기서열을 이용한 유전적 거리를 비교한 결과 국내에서 출현한 Amphidinium mootonorum 종주들은 캐나다에서 분리한 종주와 19.2%의 유전적 차이를 보여 종내 변이가 출현 종들 가운데 가장 큰 것으로 나타났다. 본 연구 해역에서 독성 와편모류인 Amphidinium carterae와 A. operculatum이 간헐적으로 출현하여 이들의 독성과 정량적인 모니터링이 추후에 필요하다.

• 한국환경과학회지
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• 제19권9호
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• pp.1083-1092
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• 2010

The spatial variability in the food chain structure of an estuary environment (Nanakita estuary, Japan) was investigated using fatty acid. Potential organic matter sources (terrestiral plants, macroalgae, benthic microalgae, dinflagellates and bacteria), sedimentary organic matters and benthic invertebrates (Nuttallia olivacea and Nereidae) were sampled in four locations with different tidal flat type. The main objective of the present study was to determine the origin of sediment and the food sources of N. olivacea and Nereidae along with small-scale spatial variability. The origin of sedimentary organic matters were mainly the fatty acid of bacteria and benthic microalgae. Especially, The organic matter of terrestrial plant origin was found the highest in station C. The diets of N. olivacea and Nereidae were found to be dominated by diatoms and terrestrial plants. Whereas, macroalgae and dinoflagellates showed little influence to benthic invertebrates. Moreover, according to principal component analysis, it is showed that benthic invertebrates in the same region are using the same food without relation with species. On the other hand, the N. olivacea and Nereidae of station D clearly contrasts with station B in terms of main food sources. From these results, it is suggested that food competition of benthic invertebrates revealed high a connection between small-scale spatial variability and food source in estuary.

• Ocean and Polar Research
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• 제34권2호
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• pp.111-123
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• 2012

To understand the phytoplankton community in the eastern part of the Yellow Sea (EYS), in the summer, field survey was conducted at 25 stations in June 2009, and water samples were analyzed using a epifluorescence microscopy, flow cytometry and HPLC method. The EYS could be divided into four areas by a cluster analysis, using phytoplankton group abundances: coastal mixing area, Anma-do area, transition water, and the central Yellow Sea. In the coastal mixing area, water column was well mixed vertically, and phytoplankton was dominated by diatoms, chrysophytes, dinoflagellates and nanoflagellates, showing high abundance ($>10^5\;cells\;l^{-1}$). In Anma-do coastal waters characterized by high dominance of dinoflagellates, high phytoplankton abundance and biomass separated from other coastal mixing area. The southeastern upwelling area was expanded from Jin-do to Heuksan-do, by a tidal mixing and coastal upwelling in the southern area of Manjae-do, and phytoplankton was dominated by benthic diatoms, nanoflagellates and Synechococcus group in this area. Phytoplankton abundance and biomass dominated by pico- and nanophytoplankton were low values in the transition waters and the central Yellow Sea. In the surface of the central Yellow Sea, high dominance of photosynthetic pigments, 19'-hexanoyloxyfucoxanthin and zeaxanthin implies that haptophytes and cyanobacteria could be the dominant group during the summer. These results indicate that the phytoplankton communities in the EYS were significantly affected by the formation of tidal front, thermal stratification, and coastal upwelling showing the differences of physical and chemical characteristics during the summer.

• 한국패류학회지
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• 제32권3호
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• pp.165-174
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• 2016

바지락의 섭식 특성을 분석하기 위해 서해의 곰소만에서 바지락의 소화관 내용물과 표층 해수의 식물플랑크톤 군집에 대해 정량 및 정성분석을 실시하였다. 바지락의 소화관에는 규조류 (71.5%), 와편모류 (13.1%), 미소플랑크톤 (6.6%) 과 중형동물플랑크톤을 포함한 유기쇄설물 등이 관찰되었다. 소화관내에서 섭식량은 겨울과 봄에 많았고 여름과 가을에 낮게 나타난 반면, 표층 해수의 식물플랑크톤 현존량은 가을에 가장 많았다. 또한 바지락의 크기가 클수록 섭식한 먹이생물의 양은 증가하였다. 소화관에서 관찰된 우점종은 저서성 규조류인 Paralia sulcata 및 Navicula arenaria와 와편모류의 cyst 이었던 반면 표층해수에서 우점종은 부유성 규조류인 Chaetoceros 속, Skeletonema 속, Asterionellopsis 속 등과 cryptomonads 및 P. sulcata이었다. 소화관 내용물 분석을 통해 바지락의 주요 먹이원은 저서성 규조류이며, 식물플랑크톤의 크기와 모양에 따라 선택적으로 섭식함을 확인하였다.

• ALGAE
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• 제36권4호
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• pp.241-261
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• 2021

Amphidinium species are amongst the most abundant benthic dinoflagellates in marine intertidal sandy ecosystems. Some of them produce a variety of bioactive compounds that have both harmful effects and pharmaceutical potential. In this study, Amphidinium cells were isolated from intertidal sand collected from the East China Sea. The two strains established were subjected to detailed examination by light, and scanning and transmission electron microscopy. The vegetative cells had a minute, irregular, and triangular-shaped epicone deflected to the left, thus fitting the description of Amphidinium sensu stricto. These strains are distinguished from other Amphidinium species by combination characteristics: (1) longitudinal flagellum inserted in the lower third of the cell; (2) icicle-shaped scales, 276 ± 17 nm in length, on the cell body surface; (3) asymmetrical hypocone with the left side longer than the right; and (4) presence of immotile cells. Therefore, they are described here as Amphidinium stirisquamtum sp. nov. The molecular tree inferred from small subunit rRNA, large subunit rRNA, and internal transcribed spacer-5.8S sequences revealed that A. stirisquamtum is grouped together with the type species of Amphidinium, A. operculatum, in a fully supported clade, but is distantly related to other Amphidinium species bearing body scale. Live A.stirisquamtum cells greatly affected the survival of rotifers and brine shrimp, their primary grazers, making them more susceptible to predation by the higher tropic level consumers in the food web. This will increase the risk of introducing toxicity, and consequently, the bioaccumulation of toxins through marine food webs.

• 환경생물
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• 제40권4호
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• pp.497-509
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• 2022

A strain of Amphidinium species was established from samples collected from the intertidal zone of a sandy beach of Jeju Island, Korea. Its cells were 13.0-15.0 ㎛ in length and 10.0-13.0 ㎛ in width. Its cell shape was round or oval and dorsoventrally flat. A pyrenoid was located in the center of the cell and a nucleus was posteriorly located. Its epicone was small and left-deflecting. Its cingulum had V-shape on the ventral side, forming a ventral ridge and extending to the sulcus. Polygonal amphiesmal vesicles and ring-shaped body scales not described previous were observed on the surface of the cell. Its morphological features were consistent with those of previously described Amphidinium fijiense. Phylogeny based on ITS region and LSU rDNA sequences revealed that this Amphidinium isolate was clearly clustered with other A. fijiense strains, but separated from other Amphidinium species. These results indicate that this Amphidinium isolate is A. fijiense. This study reports its presence for the first time in the intertidal zone of a sandy beach of Jeju Island, Korea.