• ALGAE
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• 제21권1호
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• pp.1-10
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• 2006

Genomic data is accumulating in public database at an unprecedented rate. Although presently dominated by the sequences of metazoan, plant, parasitic, and picoeukaryotic taxa, both expressed sequence tag (EST) and complete genomes of free-living algae are also slowly appearing. This wealth of information offers the opportunity to clarify many long-standing issues in algal and plant evolution such as the contribution of the plastid endosymbiont to nuclear genome evolution using the tools of comparative genomics and multi-gene phylogenetics. A particularly powerful approach for the automated analysis of genome data from multiple taxa is termed phylogenomics. Phylogenomics is the convergence of genomics science (the study of the function and structure of genes and genomes) and molecular phylogenetics (the study of the hierarchical evolutionary relationships among organisms, their genes and genomes). The use of phylogenetics to drive comparative genome analyses has facilitated the reconstruction of the evolutionary history of genes, gene families, and organisms. Here we survey the available genome data, introduce phylogenomic pipelines, and review some initial results of phylogenomic analyses of algal genome data.

• ALGAE
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• 제26권1호
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• pp.21-32
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• 2011

Studies of the red algal genus Bostrychia over the last 15 years have made it a model system for many evolutionary processes within red algal species. The combination of newly developed, or first employed methods, in red algal species studies has made Bostrychia a pioneer genus in intraspecific studies. Bostrychia was the first genus in which a mitochondrial marker was used for intraspecific red algal phylogeny, and the first for which a 3-genome phylogeny was undertaken. The genus was the first red alga used to genetically show maternal plastid and mitochondria inheritance, and also to show correlation between cryptic species (genetically divergent intraspecific lineages) and reproductive incompatibility. The chemotaxonomic use, and physiological function of osmolytes, has also been extensively studied in Bostrychia. Our continuous studies of Bostrychia also highlight important aspects in algal species studies. Our worldwide sampling, and resampling in certain areas, show that intensive sampling is needed to accurately assess the genetic diversity and therefore phylogeographic history of algal species, with increased sampling altering evolutionary hypotheses. Our studies have also shown that long-term morphological character stability (stasis) and character convergence can only be correctly assessed with wide geographic sampling of morphological species. While reproductive incompatibility of divergent lineages supports the biological species nature of these lineages, reproductive incompatibility is also seen between isolates with little genetic divergence. It seems that reproductive incompatibility may evolve quickly in red algae and the unique early stages of fertilization (e.g., gametes covered by walls, active movement of spermatium nuclei to the distant egg nucleus), also well investigated in Bostrychia,. may be key to our understanding of this process.

• Animal Systematics, Evolution and Diversity
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• 제13권2호
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• pp.141-172
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• 1997

동해 및 남해의 22종의 해조류에 서식하는 Procellidium 속의 요각류 6종을 기재하였다. 이 중에서 Porcellidium ofunatense Harris and lwasaki와 Porcellidium gamoi(harris and Iwasaki)는 한국내 미기록종이다. 나머지 4종은 신종으로 기재하였으며, 이들은 1종의 해조에서 발견된 Procellidium bipartitum n. sp., 10종의 해조에서 발견된 P.wandoensis n. sp., 5종의 해조에서 발견된 P. acutum n. sp., 그리고 2종의 해조에서 발견된 P. brevicacum n. sp.이다. Porcellidium 속의 종과 해조류 사이의 특이성은 낮게 나타났다.

• 한국수산과학회지
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• 제40권4호
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• pp.210-219
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• 2007

The benthic marine algal flora and community structure were examined at five sites of the Taean Peninsula, Korea, during July-August 2005. Ninety-six algal species were Identified, including 14 green, 21 brown, and 60 red algae, and 1 marine plant. The common species that occurred at the five sites were Sargassum thunbergii, Gelidium divaricatum, Caulacanthus okamurae, Gracilavia vermiculophylla, and Neorhodomela aculeata. Sthunbergii was the dominant species in terms of coverage and biomass at ail of the study sites. The average biomass varied from $23.72g/m^2$ in dry weight at Chaeseokpo to $66.43g/m^2$ at Padori. The species could be divided into six functional groups in terms of morphological characteristics: 41 coarsely branched forms, 25 filamentous forms, 16 sheet forms, 7 thick leathery forms, including the marine plant Phyllospadix iwatensis, 4 crustose forms, and 3 Jointed calcareous forms. The seaweed communities at the five study sites were unstable and the environmental conditions were bad or very bad. Among the five study sites, the ecological evaluation index (EEI) and diversity index (H') were maximal at Padori at 2.29 and 1.98, respectively. By contrast, the dominance index (DI) was minimal at Padori (0.55) and maximal at Baramarae (0.96). Therefore, we conclude that the rocky shore at Padori has the best environment among the five study sites, although the species richness and biomass of seaweeds have declined continuously over the last 10 years.

• Animal Systematics, Evolution and Diversity
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• 제24권2호
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• pp.219-223
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• 2008

During the long-term surveys of marine environment some ischyrocerid amphipods were collected, which indicated the various types of habitats. Among them the two species, Jassa marmarata Holmes, 1903 and J. marinai Conlan, 1990, are here reported from Korea for the first time with short redescriptions. J. marmarata occurs in the cirripedian community, while J. marinai between marine algal colonies at low tide on the rocky shore.

• ALGAE
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• 제34권4호
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• pp.289-301
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• 2019

Mixotrophy in marine organisms is an important aspect of ecology and evolution. The discovery of mixotrophic abilities in phototrophic dinoflagellates alters our understanding of the dynamics of red tides. In the phototrophic dinoflagellate genus Alexandrium, some species are mixotrophic, but others are exclusively autotrophic. There are differences in the ecological roles of autotrophic and mixotrophic Alexandrium in marine food webs. However, of the 34 known Alexandrium species, the mixotrophic ability of >20 species has yet to be explored. In this study, the mixotrophic capabilities of Alexandrium insuetum CCMP2082, Alexandrium mediterraneum CCMP3433, Alexandrium pacificum CCMP3434, Alexandrium tamutum ATSH1609, and Alexandrium margalefii CAWD10 were investigated by providing each species with 22 diverse prey items including bacterium-sized microbeads (1 ㎛), the cyanobacterium Synechococcus sp., algal prey species, and the ciliate Mesodinium rubrum. None of the 5 Alexandrium species fed on any of the prey items. These results increase the number of Alexandrium species lacking mixotrophic abilities to 9, compared to the 7 known mixotrophic Alexandrium species. Furthermore, the Alexandrium phylogenetic tree based on the large subunit ribosomal DNA contained 3 large clades, each of which had species with and without mixotrophic abilities. Thus, the acquisition or loss of mixotrophic abilities in Alexandrium might readily occur.

• ALGAE
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• 제30권2호
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• pp.103-119
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• 2015

Photosynthetic rates of the large centric diatom Coscinodiscus granii were measured by means of multicolor variable chlorophyll fluorescence imaging, single cell $^{14}C$ assimilation, and optical $O_2$ sensor measurements during light acclimatization of cultures grown at five different irradiances: 50, 150, 235, 332, and $450{\mu}mol$ photons $m^{-2}\;s^{-1}$. Photo-acclimatization was evident from changes of cellular chlorophyll a content, growth rates, and light response curves. Each of the applied methods evaluates different parts and reactions in the photosynthetic apparatus, which makes a direct quantitative comparison of rates difficult, although a different degree of correlation were found between all three methods. However, when used in combination, they provide information about the internal relationship of photosynthetic pathways as well as the variation in photosynthetic capacity between individual cells within a single algal culture.

• Animal Systematics, Evolution and Diversity
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• 제33권3호
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• pp.176-188
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• 2017

Paramenophia platysoma (Thompson and Scott, 1903) is newly reported from Korean waters based on the materials collected from several seagrass and algal bed habitats. The Korean materials of P. platysoma in the present study coincide well with the original description of the species with respects to the characteristic features of the first, fourth, and fifth legs, and in most respects to P. platysoma sensu $Gam{\hat{o}}$ (1969) reported from Japan except for the antennary exopod. However, they show some differences to P. platysoma sensu Pallares (1973, 1975) reported in Argentina, in terms of the morphology of the fifth leg in females and the second leg in males. Detailed description and illustrations of P. platysoma are provided for both sexes. The morphological features of Paramenophia species are discussed and a key to the species of genus is provided.

• Animal Systematics, Evolution and Diversity
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• 제28권4호
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• pp.221-229
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• 2012

Paranebalia longipes (Willemoes-Suhm, 1875) is cosmopolitan and has been usually found in the algal and sponge debris on the sandy mud substrates. This species can be clearly distinguished from other species of Paranebalia by the presence of serration on posterior margin of pleopods, the number of articles on antennule and antenna, and number of teeth on flange of antennule fourth article. The genus Paranebalia is new to Korea. In this paper, we provide detail descriptions of the diagnostic characteristics and illustrations of the P. longipes. Additionally, type locality and world distribution of the genus Paranebalia are provided.

• Animal Systematics, Evolution and Diversity
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• 제15권1호
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• pp.67-74
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• 1999

동해안과 남해안의 해조류에서 채집된 갈고리노벌레류 1신종 Peltidium quinquesetosum을 기재하였다. 본 종의 가장 뚜렷한 형태적 특징은 암컷의 제 1다리 내지 끝마디에 난 강모의 수와 제 5다리 모양, 그리고 꼬리마디가 후체부에 완전히 덮힌다는 점이다.