• ALGAE
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• v.17 no.1
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• pp.33-39
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• 2002

Mechanisms of competition between two canopy algae and an understory alga were investigated by a field manipulative experiment using artificial thalli. The study was carried out in the upper intertidal zone at Nudibranch Point in Vancouver Island, British Columbia, Canada, where two fucoids, Fucus gardneri and Pelvetiopsis limitata, and a turf red alga, Mazzaella cornucopiae, were dominant in the algal community. The experiment was designed to test three hypotheses, shading, whiplash, and allelopathy, imposed by potential fucoid effects on M. cornucopiae. Only the shading effect was significant, indicating that adult fucoid thalli reduced. M. cornucopiae biomass underneath the fucoids. Results indicated that reversal of competitive dominance existed between F. gardneri and M. cornucopiae depending on the life history stage of the competitors. By including the turf alga's effects on the fucoids, the well-balanced and non-hierarchical interaction networks among the major macroalgae support the high likelihood of species coexistence in the community.

• Journal of Plant Biology
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• v.37 no.4
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• pp.421-428
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• 1994

The vegetative and male reproductive anatomy of a marine alga, Laurencia intercalaris sp. nov. (Rhodomelaceae, Rhodophyta), is described from subtidal habitats of eastern and southern Korea. This species has terete thalli with entangled fibrous holdfasts and regularly alternate branching of ultimate branchlets, and is inseparable from L. okamurae Yamada on the basis of habit. Vegetative axial cells produce a trichoblast and four pericentral cells in an alternating sequence. Spermatangia are produced intercalary or subterminally from one of two laterals on suprabasal cells of trichoblasts arising from axial cells in apical pits of branchlets. The other lateral remains sterile. In this sterile lateral, budding-like regeneration occurs on older segments that are oabscised. Comparison is made with other related Laurencia species, particularly those with terete thalli. The vegetative anatomy and the regeneration in sterile laterals of male trichoblasts, with the mode of spermatangial formation, distinguish the new species from previously described species of Laurencia including L. okamurae.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.521-525
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• 2017

A marine algal species belonging to Gigartinales was collected from Geoje, Korea. This shares the generic features of Ahnfeltiopsis, such as multiaxial thalli with a compact and pseudoparenchymatous medulla, densely cytoplasmic secondary medullary cells around immersed cystocarps with a carpostome, and is distinct from similar species within the genus by a combined feature of small (up to 4 cm tall) and tuft thalli, compressed to subcompressed branches except for ultimate branchlets and base of main axes, cartilaginous in texture, dichotomous branches, rarely produced proliferations, absence of hypha-like filament in the medulla and internal cystocarps with a carpostome. In phylogenetic tree based on rbcL sequence, the Korean species nests in the same clade with Ahnfeltiopsis linearis. The genetic distance between both sequences within the clade was 1.5%, considered to be within the intra-species range for the genus. This morphological and molecular evidence confirms the Korean alga to be identified as A. linearis originally described from California. This is the first record of A. linearis in Korea.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.122-128
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• 1998

Characteristic changes in chlorophyll fluorescence from thalli of red alga, Porphyra, under high salt stress and during subsequent recovery were investigated, and the differences in the sensitivity to the stress among four species of Porphyra with different intertidal distributions were compared. By the treatment of NaCl with $9\%$ or higher concentrations, photochemical efficiency (Fv/Fm) decreased in a biphasic pattern: a rapid decrease was observed within 1­3 h and followed by a slow decline. The decrease of Fv/Fm was mainly due to the increase of Fo without significant increases of Fm. When the thalli treated with $15\%$ NaCl for 6 h were returned to natural sea water for recovery, the increase of Fv/Fm also showed a biphasic pattern: a rapid increase of Fv/Fm was observed within 2 h and followed by a slow increase. Differences in the sensitivity to salt stress among the four species could be found during recovery after the treatment of severe salt stress. After the treatment of $20\%$ NaCl for 6 h, Fv/Fm decreased below 0.3 in all of the four Porphyra species, and the species living in upper parts of the intertidal zone (P. suborbiculata and P. pseudolinearis) could recover better compared with the species in lower parts of the intertidal zone (P. seriata and P. yezoensis), during recovery for 24 h. The species collected from the coast of the South Sea seemed to be more tolerant than those in the East Sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.225-229
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• 2003

Plant ash and soil drainage, derived by frequent mountain fires during winter, might cause biological contamination to seaweeds at seashore and river mouse area. To thalli of Ulva pertusa, maximum non-lethal concentration(MNLC), lethal concentration 50 $(LC_{50})$ and minimum lethal concentration (MLC) of pine needle ash were shown as 60, 350 and 550 mg/mL, respectively. The yellow loess and granite sand did not damage at concentrations of 20 and 200 mg/mL, respectively To thalli of Porphyra yezoensis, the MNLC, LC5O, MLC of pine needle ash were shown as 0.08, 0.4 and 1.0 mg/mL, respectively. Effects of yellow loess and granite sand were approximately 1/2 and 1/10 of the ash. To thalli of Undaria pinnatifida, the pine needle ash, yellow loess and granite sand did not damage at the concentration range of 20 to 40 mg/mL. Change of pigments $(chlorophyll\;\alpha,\;lutein,\;\beta-carotene,\;phycoerthrin)$ was also determined at the MNLC, $LC-{50}$ and MLC of pine needle ash. Among three seaweeds tested, P. yezoensis produced the most 2.7-fold of lutein and 2.3-fold of $\beta-carotene$ at $LC-{50}$ of the ash. Thus the P. yezoensis, appeared as a sensitive indicator, could be used as one of test organisms for determination of the biological effect of pollutants contaminated in marine environment.

• ALGAE
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• v.24 no.4
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• pp.249-256
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• 2009

The occurrence of Laminarionema elsbetiae (Ectocarpaceae, Phaeophyceae), as epi-endophyte of Rhodymenia pseudopalmata (Rhodymeniales, Rhodophyta), described from Santa Isabel, Rawson, Argentina. L. elsbetiae grows in the host tissues forming epi-endophytic relationship in the epidermal, cortical and medullar layers. Epiphytic thalli of L. elsbetiae were unbranched filaments emerging from hostis surface. Reproductive structures of L. elsbetiae on the host were absent. On the contrary, free cultured individuals formed different reproductive structures. Macrozoosporangia containing a single large motile zoospore originated from vegetative cells, they were conical to cylindrical in shape, 30-50 ${\mu}m$ in length and 18-20 ${\mu}m$ in wide. Uniseriate plurilocular zoosporangia were cylindrical shape, 40 ${\mu}m$ in length and 10-13 ${\mu}m$ in wide. Sexual fusion was not seen. In mixed cultures of L. elsbetiae with R. pseudopalmata fronds, L. elsbetiae infected the host, grew as in natural host and, formed macrosporangia between host subcortical cells. Gametophytes of L. elsbetiae were filaments with diffuse growth, branched with a branch pattern alternate or opposite. Gametangia were plurilocular, uni or biseriate and lateral. When mature they contained 2 to 6 isogametes. The presence L. elsbetiae on R. pseudopalmata could be defined as an epi-endophytic relationship. The percentage of infection of R. pseudopalmata thalli by L. elsbetiae was 34%.A25% of the infected thalli presented a low, non-symptomatic level infection, whereas a 62% and a 13% of them exhibited respectively moderate and high indexes of infection.

• Journal of Aquaculture
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• v.4 no.1
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• pp.67-71
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• 1991

Sensitivity to ethylmethanesulphonate(EMS) on Ulva Pertusa Kjellman thalli was investigated as preliminary studies aimed at mutation breeding of seaweeds. When the thalli were grown in medium containing the mutagen no growth and about $20{\%}$ growth inhibition occurred at $0.05{\%}$ and $0.025{\%}$ EMS-mixed medium respectively. In the case the thalli were treated short time at high concentration mutagen solution followed by culture in control medium no growth and about $10{\%}$ growth inhibition occurred at 40 min. in $1.0{\%}$ and 80 min. in $0.5{\%}$ EMS solution respectively. Among the mutagenized tissues, some showed variation in growth from and cell color contrast to the mother tissue. The mutagenized tissue polypeptide pattern using sodium dodecyl sulphate-polyacrylamide gel electrophoresis was simiiar that of the mother tissue except about 6.6 kD polypeptides.

• The Korean Journal of Mycology
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• v.27 no.3 s.90
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• pp.208-210
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• 1999

Three species belong to the genus Laboulbenia were collected on Carabidae (Coleoptera) and Harpalidae (Coleoptera) from several regions of Korea. Laboulbenia anoplogenii Thaxter was collected from Stenolophus quinquepustulatus Widemann. The characters of this species are the fourth layer of receptacle consisted of two or three cells and the distal end of its posterior cell projecting upward. The thalli were produced on posterior and anterior legs of the hosts. Laboulbenia habui Terada was collected from Chlaenius variicornis Bates. This species is characterized by the basal cells of the secondary appendage composed of short-cylindrical cells, arranged alternately on a double row. The thalli were produced from the elytra and anterior abdomen of the hosts. Laboulbenia pallida Thaxter was collected from Anisodactylus signatus Panzer. This species is distinguished from other related species by the rounded tip of perithecium and the outer appendage branched on the basal cell. The thalli were produced on the posterior elytra of the hosts.

• Journal of Aquaculture
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• v.13 no.4
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• pp.295-301
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• 2000

Mature foliose thalli of P. suborbiculata f. Iatifalia were collected at Chindo, Chonnam Prefecture on 24 February 1996. Growth and reproduction were observed at selected temperatures (5~30tt photon flux densities (10-80 ${\mu}$mol m$^{-2}$s$^{-1}$) and photoperiods (14L:I00, 10L:140). The thalli grew fastest at 15 t under both photoperiods and produced archeospores at 10-$25^{\circ}C$ under both photoperiods, but zygotospores at 10-15$^{\circ}C$ under 10L:140 and at only 15$^{\circ}C$: under 14L:I00. Size and shape of the thalli at 1$0^{\circ}C$: under short photoperiod were similar to the field materials. The optimum temperature and photoperiod for growth of the conchocelis colony were 20-$25^{\circ}C$: under both photoperiods. The foliose thalli and the conchocelis filaments could not survive at 30 t. Conchosporangial branches were produced at 15-$25^{\circ}C$ under 14L:100 and 10L:140.

• Journal of Photoscience
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• v.9 no.2
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• pp.74-77
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• 2002

Chlorophyll (Chi) d was assigned to an antenna pigment of red algae in 1943, but its presence and function in red algae have not been necessarily clear for a long time. In 1996, it was shown that Chi d functioned as a major antenna pigment in a peculiar oxygenic photosynthetic prokaryote, Acaryochloris marina, isolated as a symbiont of a colonial ascidian from coral reefs. This finding evoked the necessity for reexamination of the presence and function of Chi d in red algae. We found Chi d in methanol-extract from several marine red algae, and the relative content was high in one species, Ahnfeltiopsis flabelliformis. Absorption and fluorescence spectra, HPLC analysis, and NMR and mass spectroscopy characterized Chi d extracted from the red algal thalli, and those were essentially identical to those of Chi d isolated from A. marina. However, micro-spectrophotometric analysis suggested that Chi d was not an actual constituent of the red algae but came from epiphyte(s) attached to surface of red algal thalli.