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en: Effect of different light quality on growth of juvenile Undaria pinnatifida sporophytes and holdfasts --- Wakame (Undaria pinnatifida) in Japan is mainly produced by aquaculture, and juvenile sporophytes are used as sporelings in wakame aquaculture. In this study, we used three types of LED lighting (red, green, and blue) and fluorescent light to evaluate the effects on the growth of sporophytes (blade area) and holdfasts. The daily growth rate calculated from the blade area of the sporophyte was higher at 59.5 ± 6.2% under blue light and lower at 43.0 ± 5.7% under red light. Regarding the area and a number of holdfasts, blue and fluorescent lights had a larger area and the number. On the other hand, red light had the lowest values for both. An evaluation of the above revealed that the use of blue LED is suitable for sporeling production after the fertilization of gametophytes.

ja: ワカメ幼胞子体と付着器の生長に対する光波長の影響 --- Wakame (Undaria pinnatifida) in Japan is mainly produced by aquaculture, and juvenile sporophytes are used as sporelings in wakame aquaculture. In this study, we used three types of LED lighting (red, green, and blue) and fluorescent light to evaluate the effects on the growth of sporophytes (blade area) and holdfasts. The daily growth rate calculated from the blade area of the sporophyte was higher at 59.5 ± 6.2% under blue light and lower at 43.0 ± 5.7% under red light. Regarding the area and a number of holdfasts, blue and fluorescent lights had a larger area and the number. On the other hand, red light had the lowest values for both. An evaluation of the above revealed that the use of blue LED is suitable for sporeling production after the fertilization of gametophytes.

en: Algal Resources

ja: Algal Resources


en: Optimal physical growth conditions for conchocelis of the red alga Neophyropia tenera.


en: Environmental gradients influence geographic differentiation and low genetic diversity of morphologically similar Ulva species in the Northwest Pacific

en: Botanica Marina

ja: Botanica Marina


en: 藻体抽出液を用いたスジアオノリ種苗生産に適した光量・光質条件の検討

ja: 藻体抽出液を用いたスジアオノリ種苗生産に適した光量・光質条件の検討


en: Development of an inexpensive and simple fertilizer method using plastic bottles with a semipermeable membrane for seaweed cultivation

ja: ペットボトルと半透膜を用いた安価で簡便な藻類養殖用施肥具の開発


en: Discovery of a novel siphonaxanthin biosynthetic precursor in Codium fragile that accumulates only by exposure to blue-green light

en: Photosynthetic organisms adapt to a variety of light conditions. Codium fragile, a macrosiphonous green alga, binds a unique carbonyl carotenoid, siphonaxanthin, to its major photosynthetic light-harvesting complexes, allowing it to utilize dim blue-green light for photosynthesis. Here, we describe the absolute chemical structure of a novel siphonaxanthin biosynthetic precursor, 19-deoxysiphonaxanthin, that accumulates specifically in the photosynthetic antenna only when cultivated under blue-green light. The action spectra of pigment accumulation suggest that siphonaxanthin biosynthesis is regulated by a specific wavelength profile. The results provide clues to a new acclimation mechanism to withstand hours of intense light at low tide and why siphonous algae have been growing invasively on the world's coasts for more than a century.

en: FEBS Letters

ja: FEBS Letters


en: 藻体抽出液を用いたスジアオノリ種苗生産における組織培養条件の検討

ja: 藻体抽出液を用いたスジアオノリ種苗生産における組織培養条件の検討


en: Effective use of small size shellfish discarded in the small-scale bottom trawls - On the compact culture of the Japanese cockle in an underused fishing port and the seedlings for the culture

ja: 小型底びき網漁業の投棄未利用資源の有効活用~低利用漁港を活用したとコンパクト養殖とその種苗について

en: Journal of Coastal Zone Studies

ja: 沿岸域学会誌


en: EVALUATING EFFECT OF PORTABLE FISHWAY INSTALLATION ON THE INSTREAM DISTRIBUTION OF PLECOGLOSSUS ALTIVELIS ALTIVELIS IN THE HIWASA RIVER, TOKUSHIMA PREFECTURE

ja: 徳島県日和佐川における可搬魚道の設置がアユの河川内分布におよぼす効果

en: We tested the effects of portable fishway installation in restoring upstream population of the Ayu Plecoglossus altivelis altivelis in the Hiwasa River, Japan. Roughly 60000 and 350 Ayu ascended through the portable fishway in 2018 and 2019, respectively. Density of Ayu in 2018 compared to those in 2017 was higher in the upper reaches while lower in the lower reaches, insisting that the portable fishway installation helped restoring the longitudinal connectivity for the fish species. In contrast, fishway installation of the same type in 2019 did not assist upstream migration of the fish as in 2018, partly due to the lower number of recruitments in the year and difficulty in gathering fish around the fishway entrance. Results of environmental DNA analysis correlated with snorkel counts in May 2019 but not in September 2019 in the river. Continued surveys are needed to clarify the effects of portable fishway installation in rehabilitating longitudinal connectivity in the river, as the recruitment of the fish change annually.

en: Advances in River Engineering

ja: 河川技術論文集


en: Seedling production method of Ulva prolifera using ground fragments with addition of extract from the thalli

ja: 藻体抽出液を細断細胞に添加するスジアオノリ種苗生産法

en: Stabilization of seedling production is an urgent issue in the land-based cultivation of Ulva prolifera. In this study, we established a new seedling production method, in which branching formation from ground fragments is stimulated by addition of the Solution Extracted from Homogenized Thalli (SHET) of U. prolifera. The cells in the fragments cultured with SHET differentiated into six types of cells: swelled cells, branch cells, rhizoid cells, matured cells, empty cells, or dead cells. As the amount of the added SHET increased, the proportion of the fragments with branch cells increased. The branch cells grew normally, forming leaves after 7 days of culture period. Within the tested settings, the rate of branch formation increased accordingly to the extension of storage period and increase in culture temperature. We recommend storage period of 6 weeks and incubation temperature of 25℃ for seedling production, as the increase of maturing cells at 30℃ makes seedling production unstable, especially after extended storage period.


en: Syntheses of thallusin analogues and their algal morphogenesis-inducing activities

en: Tetrahedron

ja: Tetrahedron


en: Examination of species delimitation of ambiguous DNA-based Ulva (Ulvophyceae, Chlorophyta) clades by culturing and hybridisation

en: Phycologia

ja: Phycologia


en: Curtivar improvement of Undaria pinnatifida (Harvey) Suringar by reciprocal crossing free-living male/female gametophytes between a Kagoshima natural strain and a Naruto cultivar

ja: 鹿児島県産天然ワカメと鳴門産養殖品種の雌雄フリー配偶体正逆交雑による品種改良の効果

en: Algal Resources


en: A new practical method for mass seedling production of Undaria pinnatifida (Harvey) Suringar using free-living gametophytes that originated from single zoospores and its application for commercial cultivation.

ja: 1遊走子起源のフリー配偶体を用いたワカメの大規模種苗生産法および養殖への実用化の実証


en: Light-dependent conformational change of neoxanthin in a siphonous green alga, Codium intricatum, revealed by Raman spectroscopy.

en: Siphonous green algae, a type of deep-sea green algae, appear olive drab and utilize blue-green light for photosynthesis. A siphonous green alga, Codium (C.) intricatum, was isolated from Okinawa prefecture in Japan, and a clonal algal culture in filamentous form was established. The major light-harvesting antenna was analogous to the trimeric LHCII found in higher plants, but the C. intricatum complex contained an unusual carbonyl carotenoid siphonaxanthin. Culture conditions were optimized to achieve high siphonaxanthin content in intact lyophilized filamentous bodies. Interestingly, the carotenoid composition was different when cultured under high irradiance: all-trans neoxanthin was accumulated in addition to the normal 9'-cis form in whole cell extract. Resonance Raman spectra of intact filamentous bodies, cultured under high- and low-light conditions, confirmed the accumulation of all-trans neoxanthin under high irradiance conditions. A plausible function of the presence of all-trans neoxanthin will be discussed in relation to the regulation against high light stress.

en: Photosynthesis Research

ja: Photosynthesis Research


en: Isolation and purification of the major photosynthetic antenna, fucoxanthin-Chl a/c protein, from cultured discoid germlings of the brown algae, Cladosiphon okamuranus TOKIDA(Okinawa Mozuku)

en: A chlorophyll c binding membrane intrinsic light-harvesting complex, the fucoxanthin-chlorophyll a/c protein (FCP), was isolated from cultured discoid germilings of an edible Japanese brown alga, Cladosiphon (C.) okamuranus TOKIDA (Okinawa Mozuku in Japanese). The discoid germiling is an ideal source of brown algal photosynthetic pigment-protein complexes in terms of its size and easiness of cultivation on a large scale. Ion-exchange chromatography was crucial for the purification of FCP from solubilized thylakoid proteins. The molecular weight of the purified FCP assembly was estimated to be ~56 kDa using blue native-PAGE. Further subunit analyses using 2D-PAGE revealed that the FCP assembled as a trimer consisting of two distinguishable subunits having molecular weights of 18.2 (H) and 17.5 (L) kDa. Fluorescence and fluorescence-excitation spectra confirmed that the purified FCP assembly was functionally intact.


en: Excitation Energy Transfer Dynamics of Fucoxanthin-Chlorophyll-a/c-Protein

en: Carotenoid Science

ja: Carotenoid Science


en: Novel mass production of siphonaxanthin from a green algae, "Motsure-miru(Codium intricatum)".


en: The pigment stoichiometry in a chlorophyll a/c type photosynthetic antenna.

en: The trimeric fucoxanthin-chlorophyll a/c protein (FCP) was purified from a Japanese brown alga, Cladosiphon okamuranus TOKIDA. Its pigment stoichiometry was determined to be chlorophyll (Chl) a:Chl c (1):Chl c (2):fucoxanthin = 4.6:1.1:1.0:5.5 by a combination of binary HPLC and (1)H NMR spectroscopy. No violaxanthin found bound to the FCP. The ratio of Chl c/Chl a in this FCP is amongst the highest so far reported.


en: Ultrafast excited state dynamics of fucoxanthin: excitation energy dependent intramolecular charge transfer dynamics.

en: Carotenoids containing a carbonyl group in conjugation with their polyene backbone are naturally-occurring pigments in marine organisms and are essential to the photosynthetic light-harvesting function in aquatic algae. These carotenoids exhibit spectral characteristics attributed to an intramolecular charge transfer (ICT) state that arise in polar solvents due to the presence of the carbonyl group. Here, we report the spectroscopic properties of the carbonyl carotenoid fucoxanthin in polar (methanol) and nonpolar (cyclohexane) solvents studied by steady-state absorption and femtosecond pump-probe measurements. Transient absorption associated with the optically forbidden S(1) (2(1)A) state and/or the ICT state were observed following one-photon excitation to the optically allowed S(2) (1(1)B) state in methanol. The transient absorption measurements carried out in methanol showed that the ratio of the ICT-to-S(1) state formation increased with decreasing excitation energy. We also showed that the ICT character was clearly visible in the steady-state absorption in methanol based on a Franck-Condon analysis. The results suggest that two spectroscopic forms of fucoxanthin, blue and red, exist in the polar environment.

en: Physical Chemistry Chemical Physics

ja: Physical Chemistry Chemical Physics


en: Ultrafast S1 and ICT state dynamics of a marine carotenoid probed by femtosecond one- and two-photon pump-probe spectroscopy.

en: Journal of Luminescence

ja: Journal of Luminescence


en: One- and two-photon pump-probe optical spectroscopic measurements reveal the S1 and intramolecular charge transfer states are distinct in fucoxanthin.

en: Chemical Physics Letters

ja: Chemical Physics Letters


en: Novel mass production of fucoxanthin from a brown algae, "Okinawa-Mozuku (Cladosiphon okamuranus)".


en: Effects of Fe(II) for tank cultivation of Ulva prolifera in deep seawater.

en: Algal Resources


en: Tank cultivation of Ulva prolifera in deep seawater using a new "germling cluster" method.

en: Journal of Applied Phycology

ja: Journal of Applied Phycology


en: Growth of abalone fed on Undaria pinnatifida (Alariaceae, Phaeophyceae) cultivated as free living form "germling cluster" in deep seawater.

en: Japan Journal of Phycology

ja: Japan Journal of Phycology


en: Utilization of deep seawater for the mariculture of seaweeds in Japan.


en: ホソメコンブ配偶体の生長に及ぼす硝酸塩の影響

ja: ホソメコンブ配偶体の生長に及ぼす硝酸塩の影響

en: 水産工学

ja: 水産工学


en: Fucoxanthin and Its Metabolites in Edible Brown Algae Cultivated in Deep Seawater.

en: Marine Drugs

ja: Marine Drugs


en: 香川県の低利用漁港における未利用小型トリガイのコンパクト養殖の試み -高齢漁業者と漁家女性の新たな活躍の場として-

en: 香水試研報

ja: 香水試研報