• ALGAE
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• v.30 no.1
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• pp.1-13
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• 2015

A new macroscopic riverine red algal species, Lemanea manipurensis sp. nov. (Batrachospermales) is described from Manipur in northeast India. It has a sparsely branched, pseudoparenchymatous thallus with a single, central axial filament that lacks cortical filaments. Spermatangia occur generally in isolated, low and indistinct patches or form an almost continuous ring around the axis. Carposporophytes project into the hollow thallus cavity without an ostiole. The most striking morphological feature is the carposporophyte with very short gonimoblast filaments having cylindrical, narrow and sparsely branched sterile filaments, the terminal cell of each branch with a single, large, elongate carpospore. The widely distributed L. fluviatilis has spherical carpospores in long branched chains. Phylogenetic analysis of rbcL sequence data and comparison with other Batrachospermales clearly show that our specimens do not align with other species of Lemanea and Paralemanea investigated thus far. Five specific names attributed in previous literature (1973-2014) to Lemanea from Manipur, L. australis, L. catenata, L. fluviatilis, L. mamillosa, and L. torulosa are rejected until critical anatomical and molecular evidence is available for specimens from the Manipur river systems. Taxa referable to Paralemanea were not confirmed for India in this study. In view of the high demand for food and medical uses of L. manipurensis in northeast India, conservation measures are needed for its long term survival. The present paper constitutes the first combined morphological / molecular study on a freshwater red alga from India.

• ALGAE
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• v.36 no.2
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• pp.137-146
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• 2021

Intertidal macroalgae are regularly exposed to hypo- or hypersaline conditions which are stressful. However, red algae in New Zealand are generally poorly studied in terms of salinity tolerance. Consequently, two native (Bostrychia arbuscula W. H. Harvey [Ceramiales], Champia novae-zelandiae [J. D. Hooker & Harvey] Harvey [Rhodymeniales]) and one introduced red algal taxon (Schizymenia spp. J. Agardh [Nemastomatales]) were exposed for 5 days in a controlled salt stress experiment to investigate photosynthetic activity and osmotic acclimation. The photosynthetic activity of B. arbuscula was not affected by salinity, as reflected in an almost unchanged maximum quantum yield (F_v/F_m). In contrast, the F_v/F_m of C. novae-zelandiae and Schizymenia spp. strongly decreased under hypo- and hypersaline conditions. Treatment with different salinities led to an increase of the total organic osmolyte concentrations with rising salt stress in B. arbuscula and Schizymenia spp. In C. novae-zelandiae the highest organic osmolyte concentrations were recorded at S_A 38, followed by declining amounts with further hypersaline exposure. In B. arbuscula, sorbitol was the main organic osmolyte, while the other taxa contained floridoside. The data presented indicate that all three red algal species conspicuously differ in their salt tolerance. The upper intertidal B. arbuscula exhibited a wide salinity tolerance as reflected by unaffected photosynthetic parameters and strong sorbitol accumulation under increasing salinities, and hence can be characterized as euryhaline. In contrast, the introduced Schizymenia spp. and native C. novae-zelandiae, which preferentially occur in the mid-intertidal, showed a narrower salinity tolerance. The species-specific responses reflect their respective vertical positions in the intertidal zone.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.345-358
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• 1999

To study the influences of thermal effluents flowing from hot spring on epilithic algal community, seasonal survey was carried out at stream and its watersheds from Seokjeong hot spring in Chollabuk-Do, Korea. Totally 7 points were divided into three regions fur sampling of water and epilithic algae, such as the direct effected, uneffected and the mixed region, respectively. At the discharging points of effluents, a dark-green cyanobacterial mat were remarkably constructed, mainly by two cyanobacteria, Oscillatoria and Phormidium. The mat formation were more obvious at low temperature than any other season, and even result in disappear with downstream and season. Totally, one hundred and fifty-three taxa of epilithic algae were classified with 15 unidentified species. Among the, diatoms occupied 58％ of total species, whereas cyanobacteria was 67% of total biomass, comparatively. In terms of stream direction, relative abundance of cyanobacteria was only limited in the upstream in cold season, and result in this pattern disappeared with season change. Although all physicochemical variables at the discharging points, was very high, compare to other points, they were quickly decreased downstream. Among them, some heavy metals were not detected or below the detection levels at downstream. Nitrate nitrogen increased with downstream, as well as phosphorus and sulfate have a similar trend throughout, while ammonia quickly decreased in the initial period of discharging effluents. This suggest that although the thermal effluent with high temperature and organic compounds could polluted the small study stream, various contributions such as flowing water, intake of uneffected streawater and collaboration of cyanobacterial mat and stream bottom gradually induces a stable water system.

• ALGAE
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• v.19 no.2
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• pp.79-90
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• 2004

Nuclear DNA contents of spermatia from eight ceramiacean and four dasyacean algae (Ceramiales, Rhodophyta) and microspores from two land plants were estimated by fluorescence microscopic image processing and their nuclear SSU rDNA sequence data were analyzed. In frequency distribution patterns, the DAPI-stained nuclear volume (NV) of spermatia showed two peaks corresponding to 1C and 2C. Nuclear 2C DNA contents estimated from NV were 0.45-2.31 pg in ceramiacean and 0.40-0.57 pg in dasyacean algae and 8.42-9.51 pg in two land plants, Capsicum annuum and Nicotiana tabacum. By nuclear patterning of vegetative cells derived from an apical cell, 2C DNA contents of spermatia were 2.31 pg in an alga having uninucleate and non-polyploid nucleus (Aglaothamnion callophyllidicola), 0.45-1.94 pg in algae having uninucleate and polyploid nucleus (Antithamnion spp. and Pterothamnion yezoense), and 0.40-0.62 pg in algae having multinucleate and non-polyploid nuclei (Griffithsia japonica and dasyacean algae). Each mature spermatium and microspore (pollen grain) seemed to have a 2C nucleus, which may provide a genetic buffering system to protect the genetic content of a spermatium and microspore from potentially lethal mutations. Nuclear DNA content and SSU rDNA sequence of Antithamnion sparsum from Korea were reasonably different from those of Antithamnion densum from France. The data did not support the previous taxonomic studies that these two taxa could be conspecific.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3610-3614
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• 2010

Taxonomic compositions and species diversities of the planktonic micro algae communities were investigated 8 times during the period from May, 2006 to November, 2007 in Saemangeum water regions. Total of 191 taxa were observed; 94 diatoms, 31 chlorophytes, 24 dinoflagellates, 24 cyanophytes, 11 euglenophytes, 3 silicoflagellates, 1 cryptophyte and 3 unidentified microflagellates. During the period of this study, diversity indices of the community were changed spatio-temporally and fluctuated irregularly. It was surmised that artificial factors to the water condition such as open and lock of the dike stressed to the planktonic micro algal groups.

• Journal of Korean Society on Water Environment
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• v.30 no.6
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• pp.596-604
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• 2014

This research has studied the physicochemical environmental factors and communities of epilithic diatom and phytoplanktons at Hongcheon river from December 2011 to September 2012. In case of TN, the result was hypertrophic, and for TP, it ranged from mesotrophic to eutrophic. As for BOD, Hongcheon river was rated level II or better, according to the water quality level; values were found to be below 3mg/L at most sites. Total of 83 and 114 taxa of epilithic diatom and phytoplanktons respectively, were found during the research. When assessed using the TSI, it ranged from oligomesotrophic to eutrophic. In case of DAIpo, it ranged from 64.1 to 99.5, and TDI ranged from 51.5 to74.0. These results signify good water quality, level B or better, for Hongcheon river. P-IBI was rated moderate to low, which showed higher pollution than other indices. Among the biological water quality measures analyzed in the Hongcheon river study, DAIpo best matches TDI and BOD, while TDI showed greater pollution. Therefore, P-IBI appears to be inappropriate when assessing the domestic small rivers and lakes.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.276-283
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• 2000

This study was carried out to investigate distribution of epilithic algal and chemical contents of irrigation water influencing in the Seomjin River from March to October in 1996 and 1997. In the water quality of the Seomjin River, the monthly average contents of $NH^+\;_4-N,\;SO_4\;^{2-}$ and $Cl^-$ showed the lowest peak in July and August while that of $NO_3-N$ showed the highest peak in June. The water quality of the Seomjin River was deteriorated by inflow of Yo-cheon and Sosi-cheon in the middle stream. The concentration of anions and cations of the Seomjin River was $Cl^->SO_4\;^{2-}>NO_3\;^->PO_4\;^{3-}\;and\;Ca^{2+}>Na^+>Mg^{2+}>K^+>NH_4\;^+$, respectively. The epilithic algal community identified 339 taxa consisting of 7 forma, 42 varieties and 290 species in 6 classes. In species composition, green algae and diatoms were heavily dominated which were evaluated 50.4% and 31.3% of total classification, respectively. In seasonal distribution, 219 species presented in summer but, 147 species were in winter. In this study, dominant species were Cocconeis placentula var. euglypta and Cosmarium furcatospermum in spering. Cyclotella meneghinasa and Synedra ulna, Scenedesmus ecornis in summer. Melosira varians, Achnathes minutissima in autumn and Gomphonema parvulum in winter were dominated. Finally, the dominant indices in this study have ranged 0.10-0.43.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.181-194
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• 2002

Parasitism is a one-sided relationship between two organisms in which one benefits at the expense of the other. Parasitic dinoflagellates, particularly species of Amoebophrya, have long been thought to be a potential biological agent for controlling harmful algal bloom(HAB). Amoebophrya infections have been reported for over 40 species representing more than 24 dinoflagellate genera including a few toxic species. Parasitic dinoflagellates Amoebophrya spp. have a relatively simple life cycle consisting of an infective dispersal stage (dinospore), an intracellular growth stage(trophont), and an extracellular reproductive stage(vermiform). Biology of dinospores such as infectivity, survival, and ability to successfully infect host cells differs among dinoflagellate host-parasite systems. There are growing reports that Amoebophrya spp.(previously, collectively known as Amoebophrya ceratii) exhibit the strong host specificity and would be a species complex composed of several host-specific taxa, based on the marked differences in host-parasite biology, cross infection, and molecular genetic data. Dinoflagellates become reproductively incompetent and are eventually killed by the parasite once infected. During the infection cycle of the parasite, the infected host exhibits ecophysiologically different patterns from those of uninfected host in various ways. Photosynthetic performance in autotrophic dinoflagellates can be significantly altered following infection by parasitic dinoflagellate Amoebophrya, with the magnitude of the effects over the infection cycle of the parasite depending on the site of infection. Parasitism by the parasitic dinoflagellate Amoebophrya could have significant impacts on host behavior such as diel vertical migration. Parasitic dinoflagellates may not only stimulate rapid cycling of dissolved organic materials and/or trace metals but also would repackage the relatively large sized host biomass into a number of smaller dinospores, thereby leading to better retention of host's material and energy within the microbial loop. To better understand the roles of parasites in plankton ecology and harmful algal dynamics, further research on a variety of dinoflagellate host-parasite systems is needed.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.124-133
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• 2009

Effects of substrates on the relative immigration activities (RIAs) of epilithic diatoms were examined in Sum River, a tributary of South Han River, Korea. Two hundreds of tile substrates coated with 5% agar were deposited at seven study stations (30 tiles per site) for one month from March 7 to April 7, 2008. Water sampling, physico-chemical factor measurement, and diatom analysis were performed in the field and laboratory. Over the study, major epilithic diatom species were Nitzschia amphibia, Navicula subminuscula, Cymbella minuta in both the natural and artificial substrates. Two dominant species, Nitzschia amphibia and Cymbella minuta often found at seven stations. Among all observed taxa, Nav. subminuscula and Caloneis silicula showed the highest RIA, with the value over 15 throughout the study. Regarding the algal morphology, the biraphe type species showed higher RIA than any other morph, while they comprised over 55% of total biomass, indicating a density effect. Additionally, a significant relationship between RIA and 20-day deposited substrate (p<0.05) showed in two diatom species, Nitzschia fonticola, Gomphonema quadripunctatum, which showed relatively high RIAs. These results indicate that the relative immigration activities of epilithic diatom species can be influenced by algal density in the water and substrate, nutrients, and deposited time at least 20 days.

• Journal of Fisheries and Marine Sciences Education
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• v.3 no.2
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• pp.29-46
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• 1991

Benthic marine algal community of a sea bank at Joomoonjin, in the eastern coast of Korea, was investigated monthly in view of floristic composition and seasonal periodicity during from August, 1989 to July 1990. Total number of benthic alga identified were 70 taxa, which composed of 7 species of Chlorophyta, 21 species of Phaeophyta and 42 species of Rhodophyta. The dominant species were Sargassum horneri, Underia pinnatifida, Laminaria japonica and Pachymeniopsis sp.. Vegetation, from the point of phygiognomy, was a mosaic type by these dominant species. The flora was compared with similarity index using S${\phi}$rensen coefficient and grouped by a cluster analysis. As a result, the algal community of this area could be divided into two clusters at similarity level 45% : Flora of water temperature-ascending period(January-July) and flora of water temperature-descending period(August-December). And also, the former flora was subdivided into two clusters at point of the $14^{\circ}C$ sea water temperature : winter flora(January-April) and spring-summer flora(May-July). The flora of this area was characterized as a mixed flora of cold and temperature zone by Cheney's index.