Faculty Profiles - TERADA Ryuta

Ryuta Terada, Masahiro Suzuki, Taiju Kitayama, Yoichi Sato, Gregory N. Nishihara . The phylogenetic identity and temperature effects on the photochemical efficiency of the edible green alga “Hitoegusa” (Gayralia spp., referred to as Monostroma nitidum in Japan) from Kagoshima and Okinawa, Japan . Journal of Applied Phycology 2025.12Reviewed International journal

Taiju Kitayama; Masahiro Suzuki; Ryuta Terada . First record of Ulva kanagawae V.Carneiro, N.T.Martins & Cassano (Ulvales, Chlorophyta) from Japan . Bulletin of the National Museum of Nature and Science. Series B, Botany51 ( 4 ) 127 - 135 2025.11Reviewed

Language：English Publishing type：Research paper (bulletin of university, research institution) Publisher：national Museum of Nature and Science

A brackishwater green macroalga collected from a small watercourse along the shore of Chichijima island, Ogasawara Islands, Japan was identified as Ulva kanagawae V.Carneiro, N.T.Martins & Cassano (Ulvaceae, Ulvophyceae) using the rbcL and tufA DNA sequences. Morphology of the alga from the Chichijima Island agrees with the original description of U. kanagawae in having unique twisted spirally and coiled, compressed, narrow ribbon-like thalli (less than 2 mm in width), profuse branching in the basal region, and multiseriate apices of the branches. This species, originally described in 2023 from São Paulo, Brazil, had not previously been recorded from the Pacific region.

DOI： 10.50826/bnmnsbot.51.4_127

Christophe Vieira; Shingo Akita; Masahiro Suzuki; Ryuta Terada; Takeaki Hanyuda; Satoshi Shimada; Shinya Uwai; Hiroshi Kawai . A taxonomic sudoku: Resolving the long-standing puzzle of Japanese Dictyoteae (Dictyotales, Phaeophyceae) with new records and biogeographic insights . Journal of Phycology61 ( 5 ) 1457 - 1485 2025.10Reviewed International coauthorship International journal

Ryuta Terada; Aoi Shindo; Hikari Moriyama; Narumi Shimboku; Gregory N. Nishihara . The effects of desiccation and salinity gradients in the photochemical efficiency of a mesophotic green alga, Ryuguphycus kuaweuweu (Ulvaceae) from Kagoshima, Japan . Phycological Research73 ( 4 ) 294 - 300 2025.8Reviewed International journal

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

In mesophotic coral ecosystems (MCEs) at depths of 30–40 m, the light environment is characterized by low intensity and limited spectral quality. However, due to minimal freshwater input, salinity remains relatively stable, and there are no tidal aerial exposures. We examined the effects of desiccation and salinity gradients on the photochemical efficiency of the mesophotic green alga, Ryuguphycus kuaweuweu (Ulvaceae), collected from a depth of 35 m off Mageshima Island in the northern end of the Ryukyu Islands, Japan, to evaluate its tolerance to desiccation and salinity. A pulse‐amplitude modulation (PAM) chlorophyll fluorometer was used for the measurements. Desiccation experiments, conducted for up to 4 h of aerial exposure under 50% humidity, at 20°C, and with an irradiance of 20 μmol photons m⁻2 s⁻1, revealed that the effective quantum yields (ΔF/Fm') of photosystem II dropped rapidly, approaching nearly zero after 45 min of aerial exposure. Since the decline in ΔF/Fm' was closely related to the loss of internal water from the thallus, the ΔF/Fm' decreased once the absolute water content (AWC) fell below 50% and never recovered to initial levels, suggesting a low tolerance to desiccation. Salinity experiments, conducted over 7 days under a broad range of salinities (0–100 psu), at 20°C, and with an irradiance of 20 μmol photons m⁻2 s⁻1 under a 12‐h light/12‐h dark photoperiod, demonstrated euryhaline responses, as the ΔF/Fm' of the thallus remained stable between 10 and 60 psu. Given that this alga thrives at mesophotic depths, where it is never exposed to air, it is unlikely to flourish at intertidal depths. The euryhaline characteristics of this alga might not provide an advantage in habitats without freshwater influence; however, species of Ulvaceae, which are widely found in shallow coastal areas worldwide, including estuaries, may commonly possess this euryhaline tolerance.

DOI： 10.1111/pre.70010

Ryuta Terada, Kotaro Makino, Gregory N. Nishihara . The photosynthetic response of the freshwater red alga Thorea okadae to environmental gradients of temperature, irradiance, desiccation, and salinity: Adaptations to its stream habitat . Journal of Applied Phycology37 ( 4 ) 2753 - 2768 2025.5Reviewed International journal

Masahiro Suzuki, Chiyuki Zemba, Ryuta Terada . Solieria latifolia sp. nov. and S. yoshidae sp. nov. (Solieriaceae, Rhodophyta) from offshore Tanegashima Island, Japan . Phycologia64 ( 2 ) 137 - 149 2025.5Reviewed International journal

Erik E. Sotka, Ryan B. Carnegie, James T. Carlton, Lucia Couceiro, Jeffrey A. Crooks, Hilary Heyford, Hikaru Endo, Masakazu Hori, Mitsunobu Kamiya, Gen Kanaya, Judith Kochmann, Kun-Seop Lee, Lauren Lees, Hannah Miller, Massa Nakaoka, Eric Pante, Jennifer L. Ruesink, Evangelina Schwind, Åsa Strand, Richard Taylo, Ryuta Terada, Martin Thiel, Takefumi Yorisue, Danielle Zacherl, Allan E. Strand . The genetic legacy of a global marine invader . Proceedings of the National Academy of Sciences of the United States of America122 ( 15 ) e2418730122 2025.4Reviewed International coauthorship International journal

Masahiro Suzuki; Ryuta Terada . DNA-based floristic survey of red algae (Rhodophyta) growing in the mesophotic coral ecosystems (MCEs) offshore of Tanegashima Island, northern Ryukyu Archipelago, Japan . PloS one20 ( 3 ) e0316067 - e0316067 2025.3Reviewed International journal

Language：English Publishing type：Research paper (scientific journal) Publisher：Public Library of Science (PLoS)

A molecular-based floristic survey of marine red algal biodiversity was conducted offshore Tanegashima Island, which is located at the northern end of mesophotic coral ecosystems (MCEs), in the Ryukyu Archipelago, Japan. This study provides the first comprehensive catalog of red algae comprising the sublittoral marine flora of offshore Tanegashima Island, Japan, and represents the first exhaustive molecular-assisted survey of red algal marine flora in Japan. Morphological and molecular analyses using plastid-encoded rbcL and mitochondrion-encoded cox1 genes revealed a total of 129 species, which included nine newly recognized species in Japan. Morphologically, 82 species were assigned to known species. Among the 82 species, 17 included cryptic species, and 25 appeared to have misapplied names. The remaining 47 species could not be identified to the species level, which indicates the necessity of a detailed reference library containing validated DNA barcodes and further taxonomic studies based on morpho-molecular analyses.

DOI： 10.1371/journal.pone.0316067

Ryuta Terada . Significant decline in the seaweed and seagrass communities in Kagoshima, Kyushu Island, Japan . Jeju Journal of Island Sciences2 ( 1 ) 20 - 26 2025.2Invited Reviewed International journal

Kristina M. Hill-Spanik; Hannah Rothkopf; Allan Strand; Ryan B. Carnegie; James T. Carlton; Lucia Couceiro; Jeffrey A. Crooks; Hikaru Endo; Masakazu Hori; Mitsunobu Kamiya; Gen Kanaya; Judith Kochmann; Kun-Seop Lee; Lauren Lees; Massa Nakaoka; Eric Pante; Jennifer L. Ruesink; Evangelina Schwindt; Åsa Strand; Richard Taylor; Ryuta Terada; Martin Thiel; Takefumi Yorisue; Danielle Zacherl; Erik E. Sotka . Exploring the impact of the widely introduced Pacific oyster Magallana gigas on the dispersal of Bonamia (Haplosporida): A global snapshot . Diseases of Aquatic Organisms161 39 - 46 2025.2Reviewed International coauthorship International journal

Ryuta Terada . A brown alga, Ecklonia radicosa at the southernmost distributional limit in Japan: Reconfirmation of Ecklonia radicosa from Mageshima Island, Kagoshima, the southernmost distributional limit in Japan . The Journal of Japanese Botany99 ( 4 ) 273 - 279 2024.8Reviewed

Authorship：Lead author,　Last author,　Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Tsumura & Co

A brown alga, Ecklonia radicosa (Kjellman) Okamura (Laminariales), is one of the canopy-forming algae in the kelp forest, and it is distributed at the lowest latitude among Japanese kelp species. Although the southern distributional limit of this alga is known as Mageshima Island, Kagoshima Prefecture, its presence was believed to have disappeared from this site due to climate change, as there were no records and specimens from the site for at least the last two decades. In this study, the existence of this alga was reconﬁrmed in October 2023 at a site from a depth of 35 m offshore of Mageshima Island. This alga was ﬁrst conﬁrmed on Mageshima Island in 1948. However, the latest collection’s specimen from the site, deposited at major algal herbaria, including Kagoshima University, dates back to April 1971. Even though a long-term dredge survey was conducted more than 250 times between 2006 and 2022 using T/S Nansei-Maru, Kagoshima University, E. radicosa was not conﬁrmed. In the reconﬁrmation of this alga, the blade was greatly grazed, suggesting a browsing effect by herbivorous parrotfish; however, as the sorus was confirmed at the lower portion of the blade, maturation and alternation of generations seemed to continuously occur at the study site.

DOI： 10.51033/jjapbot.ID0211

Ryuta Terada, Kyosuke Yoshizato, Kazuma Murakami, Gregory N. Nishihara . Phenology and the response of photosynthesis to irradiance and temperature gradient in the herbal drug red alga, Chondria armata (Rhodomelaceae, Ceramiales) from Kagoshima, Japan . Journal of Applied Phycology36 ( 4 ) 2139 - 2152 2024.8Reviewed International journal

Ryuta Terada; Koki Matsuda; Gregory N. Nishihara . Optimizing cultivation and shipping environments for an edible green alga, Caulerpa chemnitzia var. laetevirens (Bryopsidales) from Japan: Effects of temperature, irradiance, desiccation and salinity on photochemical efficiency . Phycological Research72 ( 2 ) 79 - 91 2024.4Reviewed International journal

Rumina Nakamura, Takuya Iwanaga, Keita Nakahara, Dai Sumiyoshi, Ryuta Terada . The effect of photochemical efficiency in cultivated Pyropia sporophytes under the conchospore-release suppression treatment resulting from postponed seeding date . Nippon Suisan Gakkaishi89 ( 6 ) 521 - 528 2023.11Reviewed

Authorship：Last author,　Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Fisheries Science

This study examined the effect of photochemical efficiency (ΔF/Fm′) in cultivated sporophytes of Pyropia yezoensis f. narawaensis under the conchospore-release suppression treatment resulting from postponement of seeding date. Two types of treatment were used to preserve sporophytes: Exp#1) Preservation in a dark aquarium tank; Exp#2) Preservation with moistened fabrics, without seawater, sealed in containers. Experiments were conducted under these two treatments for 7 days at 18 and 24℃ in the dark. In Exp#1, ΔF/Fm′ gradually decreased after culturing for more than 3 days. However, at 18℃, the values almost returned to their initial levels within one day after removing the shading. Even after the shading was removed, the values had not fully recovered after culturing for 5 and 7 days at 24℃. In Exp#2, ΔF/Fm′ was well maintained throughout the 7-day culture period at 18℃. In contrast, at 24℃, the values gradually decreased as the culture duration extended; however, after rehydration in seawater with the shading removed, the values almost fully recovered. In commercial cultivation, fishermen typically conduct these treatments for a duration of up to 3 days, suggesting that physiologically, treatments within this 3-day timeframe are likely to be appropriate.

DOI： 10.2331/suisan.23-00024

Narumi Shimboku, Ryuta Terada . Seagrass bed in Kagoshima Bay: The distribution status in 2021 and long-term decline . Nippon Suisan Gakkaishi89 ( 6 ) 510 - 520 2023.11Reviewed

Authorship：Last author,　Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Fisheries Science

In 2021, the current distribution status of seagrass beds in Kagoshima Bay, Kagoshima, Japan was investigated at 77 sites including four sites located outside the bay. At each site, we measured the seagrass bed area by the naked eye using scuba, snorkeling, and coastal walking and recorded the coverage for quadrats (50 cm long and wide), which were randomly placed inside the seagrass bed. In addition, we measured the water quality including temperature, salinity, and nitrogen levels at the study sites or in the laboratory. The results showed that five species of seagrass were confirmed from the 77 sites, including Zostera marina, Zostera japonica, Halophila nipponica, Halophila major, and Ruppia maritima. Of these species, the first three were found in Kagoshima Bay. However, the total area of seagrass beds in Kagoshima Bay drastically declined to 4.39 ha excluding 2.07 ha from outside of Kagoshima Bay, which was only 11.6% of the area observed in 2006 and 2.4% of the area observed in 1978. This decline is a serious concern for the conservation of seagrass beds in this region, particularly since Z. marina in Kagoshima Bay represents the southern distributional limit of this species in Japan.

DOI： 10.2331/suisan.23-00020

Ryuta Terada; Rumina Nakamura; Takuya Iwanaga; Keita Nakahara; Gregory N. Nishihara; . The real-time measurements of PSII photochemical efficiency in the microscopic sporophyte of Pyropia yezoensis f. narawaensis (Bangiaceae) reveals the low capacity of desiccation tolerance that drops within a few minutes of dehydration . Algal Research75 103283 2023.10Reviewed International journal

Ryuta Terada, Aoi Shindo, Hikari Moriyama, Narumi Shimboku, Gregory N. Nishihara . The response of photosynthesis to temperature and irradiance in a green alga, Ryuguphycus kuaweuweu (Ulvales) reveals adaptation to a subtidal environment in the northern Ryukyu Islands . Algal Research74 103189 - 103189 2023.6Reviewed International journal

Natsumi Shimada; Gregory N. Nishihara; Ryuta Terada . The effect of temperature and irradiance on the photosynthesis of a seagrass, Halodule uninervis from Amami-Oshima Island, Kagoshima . Nippon Suisan Gakkaishi89 ( 2 ) 115 - 126 2023.3Reviewed

Authorship：Last author,　Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japanese Society of Fisheries Science

The effect of temperature and irradiance on the photosynthesis of a tropical seagrass, Halodule uninervis, from Amami-Oshima Island, Kagoshima, Japan, close to the northern distributional limit in the western Pacific, was determined using a pulse amplitude modulation (PAM)-chlorophyll fluorometer and dissolved oxygen sensors. The response of oxygenic photosynthesis to irradiance (0–1000 µmol photons m－2 s－1) at 15 and 24℃ revealed that the maximum net photosynthesis (NPmax) was 14.7 and 51.9 μg O2 gww－1 min－1, respectively. The temperature response of gross photosynthesis (8–40℃) showed that the highest gross photosynthetic rate occurred at 30.5℃ (ToptGP). In contrast, the temperature response of the maximum quantum yield (Fv/Fm) of photosystem II after 3 days of cultivation in darkness revealed that Fv/Fm gradually increased to the optimal temperature (ToptFv/Fm) of 23.9℃, then gradually declined at higher temperatures. The combined effects of 12-hour chronic exposure to temperature and irradiance at 15 and 24℃, under 300 and 1000 μmol photons m－2 s－1 showed that the depression of Fv/Fm was more pronounced under low temperature with high irradiance, indicating the occurrence of chronic low temperature-light stress.

DOI： 10.2331/suisan.22-00035

uka Toyoya (Koyano, Masato Hirose, Tomoyuki Nakano, Hironori Komatsu, Ryuta Terada, Takashi Toyofuku, Yukiko Nagai, Hitoshi Imai, Yusuke Oyamada, Akitsugu Mukai, Dairou Kawaguchi, Ryuichi Minato, Hideaki Mori, Hiroshi Miyake . Preliminary report of marine macrofauna of Nishinoshima Island . Ogasawara Research49 113 - 168 2023.3

Yukiko Yonemori; Shogo Kokubu; Gregory N. Nishihara; Hikaru Endo; Ryuta Terada . The effects of desiccation and salinity gradients in the PSII photochemical efficiency of an intertidal brown alga, Sargassum fusiforme from Kagoshima, Japan . Phycological Research71 ( 1 ) 3 - 12 2023.1Reviewed International journal

Tomohiro Ito; Toui Yoshioka; Hiromori Shimabukuro; Gregory N. Nishihara; Hikaru Endo; Ryuta Terada . The effect of temperature, light‐spectrum, desiccation and salinity gradients on the photosynthetic performance of a subtidal brown alga, Sargassum macrocarpum, from Japan . Phycological Research71 ( 1 ) 25 - 36 2023.1Reviewed International journal

Natsumi Shimada; Iori Tatamidai; Gregory N. Nishihara; Ryuta Terada . The effect of temperature and light on the photosynthesis of annual Zostera marina seedlings from Kagoshima, Japan . Nippon Suisan Gakkaishi88 ( 6 ) 472 - 484 2022.11Reviewed

Authorship：Last author,　Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japanese Society of Fisheries Science

The effect of temperature and light on the photosynthesis of seedlings of Zostera marina from the annual population in Kagoshima, Japan was determined by field and laboratory measurements using a pulse amplitude modulation (PAM)-chlorophyll fluorometer. The response of oxygenic photosynthesis to temperature (8-40℃) was also examined with dissolved oxygen sensors to compare with effective quantum yields (ΔF/Fm′) of photosystem II. The temperature response of ΔF/Fm′ under 50 μmol photons m−2 s−1 (12L12D photoperiod) and during five days of cultivation revealed that ΔF/Fm′ gradually increased to the optimal temperature at 23.1℃ (ToptΔF/Fm′; 19.0-27.4℃), then quickly declined at higher temperatures. The 12-hour chronic combined effects of temperature and light at 8 and 20℃, under 200 and 1,000 μmol photons m−2 s−1 showed that the depression of ΔF/Fm′ was more pronounced under the low temperature with high light, indicating the occurrence of chronic low temperature-light stress. The temperature response of the oxygenic gross-photosynthesis curve indicated an optimal temperature at 31.0℃ (ToptGP; 28.4-33.2℃), then declined at higher temperatures. The underwater measurements of natural communities of Z. marina in Kagoshima showed that ΔF/Fm′ declined with increasing incident light, with a minimum occurring during noon to early afternoon. Nevertheless, ΔF/Fm′ recovered by sunset.

DOI： 10.2331/suisan.22-00011

Other Link： https://www.jstage.jst.go.jp/article/suisan/88/6/88_22-00011/_pdf/-char/ja

Natsumi Shimada; Gregory N. Nishihara; Ryuta Terada . Diurnal change of the photochemical efficiency in a seagrass, Enhalus acoroides, based on the measurement under incident sunlight . Aquaculture Science70 ( 3 ) 277 - 280 2022.10Reviewed

Authorship：Last author,　Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society for Aquaculture Science

The diurnal change in photochemical efficiency of a seagrass, Enhalus acoroides was determined in Okinawa, Japan. The measurements under incident sunlight were conducted from sunrise through sunset using a submersible pulse amplitude modulation (PAM)-chlorophyll fluorometer (Diving-PAM). The effective quantum yield (ΔF/Fm’) declined with increasing incident sunlight in the morning, with a ΔF/Fm’ minima occurring during noon-time. Thereafter, the ΔF/Fm’ gradually recovered during the afternoon incident sunlight decreased, indicating a dynamic negative response to the excess sunlight. The decline of ΔF/Fm’ in the habitat is likely a photoprotective response to protect the photosynthetic reaction center from damage by excess light energy.

File： Shimada_2022_Enhalus_Aquaculture_Science_277-280.pdf

DOI： 10.11233/aquaculturesci.70.277

Clyde Puilingi; Suh Nih Tan; Yukari Maeno; Chui Pin Leaw; Po Teen Lim; Mari Yotsu-Yamashita; Ryuta Terada; Yuichi Kotaki . First record of the diatom Nitzschia navis-varingica (Bacillariophyceae) producing amnesic shellfish poisoning-toxins from Papua New Guinea . Toxicon216 65 - 72 2022.9Reviewed International coauthorship International journal

Yamada Motomi, Maeno Yukari, Kotaki Yuichi, Terada Ryuta, Hidaka Masafumi, Kudo Yuta, Cho Yuko, Konoki Keiichi, Yamashita Mari Yotsu- . Preparation of domoic acid and kainic acid analogues using the cyclases, and evaluation of their toxicities . Symposium on the Chemistry of Natural Products, symposium papers64 ( 0 ) 301 - 304 2022.8

Aoi Shindo; Gregory N. Nishihara; Iris Ann Borlongan; Ryuta Terada . Interactive effects of temperature and irradiance including spectral light quality on the photosynthesis of a brown alga Saccharina japonica (Laminariales) from Hokkaido, Japan . Algal Research 2022.7Reviewed International coauthorship International journal

Yoichi Sato; Gregory N. Nishihara; Atsuko Tanaka; Dominic F. C. Belleza; Azusa Kawate; Yukio Inoue; Kenjiro Hinode; Yuhei Matsuda; Shinichiro Tanimae; Kandai Tosaki; Ryuta Terada; Hikaru Endo . Variability in the net ecosystem productivity (NEP) of seaweed farms . Frontiers in Marine Science9 861932 2022.5Reviewed

Aoi Shindo; Gregory N. Nishihara; Iris Ann Borlongan; Ryuta Terada . The effects of desiccation and salinity gradients in the photochemical efficiency of a subtidal brown alga, Saccharina japonica (Laminariales) from Hokkaido, Japan . Phycological Research70 ( 2 ) 89 - 96 2022.4Reviewed International coauthorship International journal

Taylor S. Steele; John K. Brunson; Yukari Maeno; Ryuta Terada; Andrew E. Allen; Mari Yotsu-Yamashita; Jonathan R. Chekan; Bradley S. Moore; . Domoic acid biosynthesis in the red alga Chondria armata suggests a complex evolutionary history for toxin production . Proceedings of the National Academy of Sciences of the United States of America119 ( 6 ) e211740711 2022.2Reviewed International coauthorship International journal

Yoichi Sato, Daisuke Saito, Gregory N. Nishihara, Ryuta Terada . Effects of different stressors on the PSII photochemical efficiency and application to sporeling transportation in cultured young sporophytes of Undaria pinnatifida . Journal of Applied Phycology34 ( 1 ) 551 - 563 2022.2Reviewed International journal

Takahiro Kurahori, Hiromori Shimabukuro, Ryuta Terada, . Phenology and environmental characteristics of two species of Sargassum (Fucales), S. hemiphyllum and S. glaucescens from Kagoshima Bay, Japan . Nippon Suisan Gakkaishi88 ( 1 ) 12 - 19 2022.1Reviewed

Ryuta Terada, Aoi Shindo, Miwa Tanaka, Satoshi Esaki . Long-term change in seaweed assemblages in Nagashima Island, Kagoshima Prefecture: Disappearance of the canopy-forming kelp and fucoid algae from coastal areas facing the East China Sea . Nippon Suisan Gakkaishi87 ( 6 ) 631 - 641 2021.11Reviewed

Stacy A. Krueger-Hadfield, James E. Byers, Guido Bonthond, Ryuta Terada, Florian Weinberger, Erik E. Sotka . Intraspecific diversity and genetic structure in the widespread macroalga Agarophyton vermiculophyllum. . Journal of Phycology57 ( 5 ) 1403 - 1410 2021.10Reviewed International coauthorship International journal

Masahiro Suzuki, Ryuta Terada . Morpho-anatomical and molecular reassessments of Rhodymenia prostrata (Rhodymeniaceae, Rhodophyta) from Japan support the recognition of Halopeltis tanakae nom. nov. . Phycologia 2021.8Reviewed International journal

Yukari Maeno, Yuichi Kotaki, Ryuta Terada, Masafumi Hidaka, Yuko Cho, Keiichi Konoki, and Mari Yotsu-Yamashita . Preparation of domoic acid analogues using a bioconversion system and their toxicity in mice . Organic & Biomolecular Chemistry19 7894 2021.8Reviewed International journal

Kenjiro Hinode, Hoshimi Kamisaki, Gregory N. Nishihara, Ryuta Terada . The phenology of epiphytic diatoms and epifauna observed on Zostera marina of Arikawa Bay, Nagasaki Prefecture, Japan . Plankton and Benthos Research16 ( 3 ) 179 - 190 2021.8Reviewed International journal

Yoichi Sato, Hikari Nagoe, Gregory N. Nishihara, Ryuta Terada . The photosynthetic response of cultivated juvenile and mature Undaria pinnatifida (Laminariales) sporophytes to light and temperature . Journal of Applied Phycology33 ( 5 ) 3437 - 3448 2021.7Reviewed International journal

Gangping Xu, Ryuta Terada, Yuki Watanabe, Gregory N. Nishihara . The occurrence of Phycocalidia tanegashimensis (Bangiaceae) in the splash zone may be related to the tolerance of photochemical efficiency to temperature, irradiance, desiccation, and salinity . Journal of Applied Phycology33 ( 5 ) 3427 - 3435 2021.5Reviewed International coauthorship International journal

Ryo Kameyama, Gregory N. Nishihara, Chikara Kawagoe, Ryuta Terada . The effects of four stressors, irradiance, temperature, desiccation, and salinity on the photosynthesis of a red alga, Agarophyton vermiculophyllum (Gracilariales) from a native distributional range in Japan . Journal of Applied Phycology33 ( 4 ) 2561 - 2575 2021.5Reviewed International journal

Ryuta Terada, Gregory N. Nishihara, Kaname Arimura, Yuki Watanabe, Takayuki Mine, Tarou Morikawa . Photosynthetic response of a cultivated red alga, Neopyropia yezoensis f. narawaensis (= Pyropia yezoensis f. narawaensis; Bangiales, Rhodophyta) to dehydration stress differs with between two heteromorphic life-history stages . Algal Research55 2021.4Reviewed International journal

Ryuta Terada, Moe Takaesu, Iris Ann Borlongan, Gregory N. Nishihara . The photosynthetic performance of a cultivated Japanese green alga Caulerpa lentillifera in response to three different stressors, temperature, irradiance, and desiccation . Journal of Applied Phycology33 ( 4 ) 2547 - 2559 2021.3Reviewed International coauthorship International journal

Masahiro Suzuki, Ryuta Terada . A new flattened species of Gracilariopsis (Gracilariales, Rhodophyta) from Japan . Phycologia60 ( 2 ) 158 - 163 2021.3Reviewed International journal

Tomohiro Ito, Iris Ann Borlongan, Gregory N. Nishihara, Hikaru Endo, Ryuta Terada . The effects of irradiance, temperature, and desiccation on the photosynthesis of a brown alga, Sargassum muticum (Fucales), from a native distributional range in Japan . Journal of Applied Phycology33 2021.3Reviewed International coauthorship International journal

Gangping Xu, Ryuta Terada, Yuki Watanabe, Gregory N. Nishihara . Temperature characteristics on the growth and photosynthesis of a red alga, Phycocalidia tanegashimensis (= Pyropia tanegashimensis, Bangiales) reveal adaptation to subtropical environments due to year-round occurrence of the macroscopic gametophyte . Journal of Applied Phycology33 2021.3Reviewed International coauthorship International journal

Iris Ann Borlongan; Ryuta Terada; Anicia Hurtado . Concise review of the genus Meristotheca (Rhodophyta: Solieriaceae) . Journal of Applied Phycology33 ( 1 ) 167 - 181 2021.2Invited Reviewed International coauthorship

Hiroshi Kawai, Takeaki Hanyuda, Ichiro Mine, Shinichi Takaichi, Ryuta Terada, Taiju Kitayama . Morphology and molecular phylogeny of Umbraulva spp. (Ulvales, Ulvophyceae), and proposal of Ryuguphycus gen. nov. and R. kuaweuweu comb. nov. . European Journal of Phycology56 ( 1 ) 1 - 11 2021.2Reviewed International journal

Ryuta Terada, Mahiko Abe, Takuzo Abe, Masakazu Aoki, Akihiro Dazai, Hikaru Endo, Mitsunobu Kamiya, Hiroshi Kawai, Akira Kurashima, Taizo Motomura, Noboru Murase, Yoshihiko Sakanishi, Hiromori Shimabukuro, Jiro Tanaka, Goro Yoshida, Misuzu Aoki . Japan's nationwide long‐term monitoring survey of seaweed communities known as the “ Monitoring Sites 1000 ”: Ten‐year overview and future perspectives . Phycological Research69 ( 1 ) 12 - 30 2021.1Invited Reviewed International journal

Masahiro Suzuki, Ryuta Terada, Kensuke Shibata, Hiroshi Kawai . New records of Chondracanthus saundersii and Schottera koreana (Gigartinales, Rhodophyta) from Japan based on molecular and morphological analyses . Phycological Research 2020.11Reviewed International journal

Iris Ann Borlongan, Ryo Arita, Gregory N. Nishihara, Ryuta Terada . The effects of temperature and irradiance on the photosynthesis of two heteromorphic life history stages of Saccharina japonica (Laminariales) from Japan . Journal of Applied Phycology32 ( 6 ) 4175 - 4187 2020.10Reviewed International coauthorship International journal

Kenjiro Hinode, Peeraporn Punchai, Mako Saitsu, Gregory N. Nishihara, Yukio Inoue, Ryuta Terada . The phenology of gross ecosystem production in a macroalga and seagrass canopy is driven by seasonal temperature . Phycological Research68 ( 4 ) 298 - 312 2020.10Reviewed International journal

Ryuta Terada, Tomohiro Yuge, Yuki Watanabe, Takayuki Mine, Tarou Morikawa, Gregory N. Nishihara . Chronic effects of three different stressors, irradiance, temperature, and desiccation, on the PSII photochemical efficiency in the heteromorphic life-history stages of cultivated Pyropia yezoensis f. narawaensis (Bangiales) from Japan . Journal of Applied Phycology32 ( 5 ) 3273 - 3284 2020.10Reviewed International journal

Yukio Inoue, Ryuta Terada, Dominic F. C. Belleza, Gregory N. Nishihara . Effect of water velocity on the physiology of a collapsing Sargassum siliquastrum canopy under a controlled environment . Phycological Research68 ( 4 ) 313 - 322 2020.10Reviewed International journal

Yoichi Sato, Jumpei Kozono, Gregory N. Nishihara, Ryuta Terada . Effect of light and temperature on photosynthesis of a cultivated brown alga, Saccharina sculpera (Laminariales), from Japan . Phycologia59 ( 4 ) 375 - 385 2020.7Reviewed International journal

Jumpei Kozono, Gregory N. Nishihara, Hikaru Endo, Ryuta Terada . Photosynthetic activity in two heteromorphic life-history stages of a freshwater red alga, Thorea gaudichaudii (Thoreales) from Japan, in response to an irradiance and temperature gradient . Phycological Research68 ( 3 ) 191 - 202 2020.7Reviewed International journal

Hiroshi Kawai, Ryuta Terada, Takeaki Hanyuda . Molecular phylogeny of Punctaria mageshimensis reveals evidence for its transfer to Spatoglossum as S. mageshimense (Dictyotales, Phaeophyceae) . Phycological Research68 ( 3 ) 203 - 207 2020.7Reviewed International journal

Yukio Inoue, Koichi Osaki, Ryuta Terada, Gregory N. Nishihara . Effects of seaweed deformation on photosynthesis rate and nutrient uptake rate . Japanese Journal of Phycology68 ( 1 ) 1 - 8 2020.3Reviewed

Iris Ann Borlongan, Sayuri Suzuki, Gregory N. Nishihara, Jumpei Kozono, Ryuta Terada . Effects of light quality and temperature on the photosynthesis and pigment content of a subtidal edible red alga Meristotheca papulosa (Solieriaceae, Gigartinales) from Japan . Journal of Applied Phycology32 ( 2 ) 1329 - 1340 2020.2Reviewed International coauthorship International journal

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Nature

This study investigated the effects of different light spectral qualities and temperature on the photosynthesis and pigment content of a subtidal edible red alga, Meristotheca papulosa. Photosynthesis–irradiance (P–E) experiments were carried out under red (660 nm), blue (450 nm), green (525 nm, light-emitting diodes), and white light (visible light, metal halide lamp), and at 12, 20, and 28 °C, respectively. Maximum net photosynthetic rates (NPmax) were highest under green light. Other P–E parameter estimates were similar among algae under red, blue, and green light, including their lower initial slope (α) and higher saturation irradiances (Ek) as compared to those under white light. Additionally, NPmax and Ek under white light were highest at 28 °C, and lowest at 12 °C with characteristic photoinhibition at irradiances greater than 150 μmol photons m−2 s−1. Photosynthesis–temperature (P–T) experiment revealed that the maximum gross photosynthetic rate (GPmax) occurred at 22.1 °C, which was within the optimal temperature range of Fv/Fm (21.5–23.6 °C). Exposures to the different light qualities at 100 μmol photons m−2 s−1 for 7 days showed increased phycoerythrin (PE) concentration of algae under blue and green light, while chlorophyll-a and phycocyanin (PC) showed little variation in all light qualities. Therefore, considering future management prospects for M. papulosa mariculture, we suggest that green light could be utilized to enhance photosynthesis. Furthermore, if the aim is to achieve high PE content for an improved reddish-color fresh product, exposure to blue or green light could be a good alternative.

DOI： 10.1007/s10811-020-02045-z

Jumpei Kozono, Gregory N. Nishihara, Hikaru Endo, Ryuta Terada . The temperature and light responses on the photosynthesis of two freshwater red algae, Virescentia helminthosa and Sheathia arcuata (Batrachospermaceae), from Japan . Journal of Applied Phycology32 ( 2 ) 1341 - 1352 2020.1Reviewed International journal

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Nature

The temperature and light responses of photosynthesis in two freshwater red algae, Virescentia helminthosa and Sheathia arcuata (Batrachospermaceae), were determined by a pulse amplitude modulation (PAM) chlorophyll fluorometer and dissolved oxygen sensors. Net oxygenic photosynthesis–photosynthetically active radiation (PAR) models of V. helminthosa and S. arcuata revealed similar low PAR-adapted responses, with a compensation PAR (Ec) of 6.95 and 11.5 μmol photons m−2 s−1 (5.58–8.42 and 9.10–11.42, 95% Bayesian prediction interval, BPI) and saturating PAR (Ek) of 18.8 and 17.7 μmol photons m−2 s−1 (14.5–24.7 and 13.0–23.90, BPI), respectively. A temperature-dependent model of net photosynthesis and dark respiration for two species also showed similar temperature responses, and the gross photosynthetic rate (GPmax), 1.79 and 1.19 μg O2 gww−1 min−1 (1.62–1.96 and 1.08–1.29, BPI), was highest at 26.4 and 30.3 °C (23.9–28.7 and 28.3–32.1, BPI). The maximum quantum yields (Fv/Fm) for two species also had similar responses with respect to temperature; however, it was generally stable at low temperatures (8–20 °C) with the highest value of 0.52 and 0.56 (0.49–0.54 and 0.54–0.58, BPI) occurring at 18.5 and 20.9 °C (17.1–19.7 and 19.8–21.9, BPI). Continuous exposure (12 h) to PAR of 100 (low) and 1000 (high) μmol photons m−2 s−1 at 12, 16, and 24 °C revealed greater declines in their effective quantum yield (ΦPSII) in the two species under high PAR. Nevertheless, their Fv/Fm mostly recovered after a subsequent 12-h dim-light acclimation, suggesting the potential of recovery from daytime chronic photoinhibition.

DOI： 10.1007/s10811-019-01967-7

Ryuta Terada, Yuto Nakashima, Iris Ann Borlongan, Hiromori Shimabukuro, Jumpei Kozono, Hikaru Endo, Satoshi Shimada, Gregory N. Nishihara . Photosynthetic activity including the thermal- and chilling-light sensitivities of a temperate Japanese brown alga Sargassum macrocarpum . Phycological Research68 ( 1 ) 70 - 79 2020.1Reviewed International coauthorship International journal

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

The effects of irradiance, temperature, thermal- and chilling-light sensitivities on the photosynthesis of a temperate alga, Sargassum macrocarpum (Fucales) were determined by a pulse amplitude modulation (PAM)-chlorophyll fluorometer and dissolved oxygen sensors. Oxygenic photosynthesis–irradiance curves at 8, 20, and 28°C revealed that the maximum net photosynthetic rates (NPmax) and saturation irradiance were highest at 28°C, and lowest at 8°C. Gross photosynthesis and dark respiration determined over a range of temperatures (8–36°C) at 300 μmol photons m−2 s−1 revealed that the maximum gross photosynthetic rate (GPmax) occurred at 27.8°C, which is consistent with the highest seawater temperature in the southern distributional limit of this species in Japan. Additionally, the maximum quantum yields of photosystem II (Fv/Fm) during the 72-h temperature exposures were stable at 8–28°C, but suddenly dropped to zero at higher temperatures, indicative of PSII deactivation. Continuous exposure (12 h) to irradiance of 200 (low) and 1000 (high) μmol photons m−2 s−1 at 8, 20, and 28°C revealed greater declines in their effective quantum yields (ΦPSII) under high irradiance. While ΦPSII under low irradiance were very similar with the initial Fv/Fm under 20 and 28°C, values rapidly decreased with exposure duration at 8°C. At this temperature, Fv/Fm did not recover to initial values even after 12 h of dark acclimation. Final Fv/Fm of alga at 28°C under high irradiance treatment also did not recover, suggesting its sensitivity to photoinhibition at both low and high temperatures. These photosynthetic characteristics reflect both the adaptation of the species to the general environmental conditions, and its ability to acclimate to seasonal changes in seawater temperature within their geographical range of distribution.

DOI： 10.1111/pre.12398

Hiroshi Kawai, Takeaki Hanyuda, Ryuta Terada . Long-term monitoring of macroalgal communities: Ten-year overview . Bulletin of Kansai Organization for Nature Conservation42 ( 2 ) 111 - 119 2020.1

Ga Hun Boo, Ying Xiong Qiu, Jung Yeon Kim, Put O. Ang Jr, Samuel Bosch, Olivier De Clerck, Peimin He, Atsushi Higa, Bangqin Huang, Kazuhiro Kogame, Shao Lun Liu, Tu van Nguyen, Shoichiro Suda, Ryuta Terada, Kathy Ann Miller, Sung Min Boo . Contrasting patterns of genetic structure and phylogeography in the marine agarophytes Gelidiophycus divaricatus and G. freshwateri (Gelidiales, Rhodophyta) from East Asia . Journal of Phycology55 ( 6 ) 1319 - 1334 2019.11Reviewed International coauthorship International journal

Yukari Maeno, Ryuta Terada, Yuichi Kotaki, Yuko Cho, Keiichi Konoki, Mari Yotsu-Yamashita . Possible biosynthetic products and metabolites of Kainic acid from the red alga Digenea simplex and their biological activity . Journal of Natural Products82 ( 6 ) 1627 - 1633 2019.5Reviewed International coauthorship International journal

Iris Ann Borlongan, Yusuke Maeno, Jumpei Kozono, Hikaru Endo, Satoshi Shimada, Gregory N. Nishihara, Ryuta Terada . Photosynthetic performance of Saccharina angustata (Laminariales, Phaeophyceae) at the southern boundary of subarctic kelp distribution in Japan . Phycologia58 ( 3 ) 300 - 309 2019.5Reviewed International journal

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Taylor & Francis

Effects of photosynthetically active radiation (PAR) and temperature on the photosynthesis of a subarctic edible brown alga, Saccharina angustata (Laminariaceae, Laminariales), from Hokkaido, Japan, were determined using a pulse amplitude modulation (PAM)–chlorophyll fluorometer and optical dissolved oxygen sensors. Photosynthesis–PAR experiments at 8, 16, and 20 °C revealed highest net photosynthetic rates at 16 °C; whereas, the temperature effect on maximum quantum yield (Fv/Fm) showed the highest Fv/Fm at 7.0 to 8.4 °C. These temperatures corresponded to the optimum temperatures for growth of Japanese Saccharina species. The maximum gross photosynthetic rate from gross photosynthesis–temperature curve was at 21.2 °C. Though consistent with the highest seawater temperature in the study site, it is close to the limit for thermal inhibition, because Fv/Fm above 20 °C was compromised after 48–72 h of incubation. Continuous 6-h exposures to PAR of 200 µmol (low) and 1000 µmol (high) photons m−2 s−1 at 8, 16, and 20 °C caused chronic photoinhibition in the alga, with greater declines in effective quantum yields of photosystem II (ΦPSII) and failure of recovery in post-dark acclimation Fv/Fm under high PAR. This physiological performance provides a basis for understanding the persistence of S. angustata near its southern boundary in the western Pacific.

DOI： 10.1080/00318884.2019.1571355

Ryuta Terada, Keita Nakahara, Iris Ann Borlongan, Yuki Watanabe, Takayuki Mine, Tarou Morikawa, Tadamitsu Igari, Hiromi Nishi, Hikaru Endo, Gregory N. Nishihara . Combined effects of irradiance and temperature on the PSII photochemical efficiency in the heteromorphic life history stages of cultivated Pyropia (Bangiales): P. yezoensis f. narawaensis and P. tenera from Japan . Journal of Applied Phycology31 ( 2 ) 1251 - 1257 2019.4Reviewed International journal

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Nature

The combined effects of irradiance and temperature on photosystem II (PSII) photochemical efficiency were investigated in the microscopic sporophyte and macroscopic gametophyte stages of the cultivated red algae Pyropia yezoensis f. narawaensis and Pyropia tenera (Bangiales) from Kyushu Island, Japan. Continuous 12-h exposures to 10, 100, and 1000 molphotonsm(-2)s(-1) at 8, 20, and 28 degrees C revealed that sporophyte and gametophyte stages of both species have different tolerance characteristics to irradiance and temperature. Effective quantum yields (phi(PSII)) of sporophytes declined at 100 and 1000molphotonsm(-2)s(-1), and their maximum quantum yields (F-v/F-m) did not fully recover even after 12h of dark acclimation, indicating photodamage. Furthermore, this depression was greatest at 8 degrees C, suggesting low temperature-enhanced photoinhibition. Larger declines of phi(PSII) and subsequent failure of F-v/F-m recovery in the gametophyte were observed only at 1000 mol photons m(-2)s(-1), suggesting that the macroscopic stage is more tolerant to relatively higher irradiance than the sporophyte. Farming protocols, including the timing of conchospore seeding, as well as depth range and duration for Nori-net cultivation need to be optimized to ensure sustainable production of these high-valued seaweed cultivars.

DOI： 10.1007/s10811-018-1621-0

Other Link： https://link.springer.com/article/10.1007/s10811-018-1621-0

Rika Fukumoto, Iris Ann Borlongan, Gregory N. Nishihara, Hikaru Endo, Ryuta Terada . Effect of photosynthetically active radiation and temperature on the photosynthesis of two heteromorphic life history stages of a temperate edible brown alga, Cladosiphon umezakii (Chordariaceae, Ectocarpales), from Japan . Journal of Applied Phycology31 ( 2 ) 1259 - 1270 2019.4Reviewed International journal

Norico Yamada, Mahmutjan Dawut, Ryuta Terada, Takeo Horiguchi . Plagiodinium ballux sp. nov. (Dinophyceae), a deep (36 m) sand dwelling dinoflagellate from subtropical Japan . Phycological Research67 ( 1 ) 12 - 20 2019.1Reviewed International journal

Iris Ann Borlongan, Gregory N. Nishihara, Satoshi Shimada, Ryuta Terada . Assessment of photosynthetic performance in the two life history stages of Alaria crassifolia (Laminariales, Phaeophyceae) . Phycological Research67 ( 1 ) 28 - 38 2019.1Reviewed International journal

Yukari Maeno, Yuichi Kotaki, Ryuta Terada, Yuko Cho, Keiichi Konoki, Mari Yotsu-Yamashita . Six domoic acid related compounds from the red alga, Chondria armata, and domoic acid biosynthesis by the diatom, Pseudo-nitzschia multiseries . Scientific Reports8 ( 1 ) 356 2018.12Reviewed International journal

Language：English Publishing type：Research paper (scientific journal) Publisher：Nature Publishing Group

Domoic acid (DA, 1), a potent neurotoxin that causes amnesic shellfish poisoning, has been found in diatoms and red algae. While biosynthetic pathway towards DA from geranyl diphosphate and l-glutamate has been previously proposed, its late stage is still unclear. Here, six novel DA related compounds, 7′-methyl-isodomoic acid A (2) and B (3), N-geranyl-l-glutamic acid (4), 7′-hydroxymethyl-isodomoic acid A (5) and B (6), and N-geranyl-3(R)-hydroxy-l-glutamic acid (7), were isolated from the red alga, Chondria armata, and their structures were determined. The compounds 4 and 7, linear compounds, are predictable as the precursors to form the DA pyrrolidine ring. The compounds 2 and 3 are thought as the cyclized products of 7
therefore, dehydration and electron transfer from the internal olefin of 7 is a possible mechanism for the pyrrolidine ring formation. One terminal methyl group of the side chain of 2 and 3 is predicted to be oxidized to hydroxymethyl (5, 6), and then to carboxylic acids, forming isodomoic acids A and B. Finally, the terminal olefin of isodomoic acid A would be isomerized to form DA. In addition, [15N, D]-labeled 4 was incorporated into DA using the diatom, Pseudo-nitzschia multiseries, demonstrating that 4 is the genuine precursor of DA.

DOI： 10.1038/s41598-017-18651-w

Other Link： https://www.nature.com/articles/s41598-017-18651-w

Jumpei Kozono, Gregory N. Nishihara, Hikaru Endo, Ryuta Terada . Effect of temperature and PAR on photosynthesis of an endangered freshwater red alga, Thorea okadae, from Kagoshima, Japan . Phycologia57 ( 6 ) 619 - 629 2018.11Reviewed International journal

Rika Fukumoto, Iris Ann Borlongan, Gregory N. Nishihara, Hikaru Endo, *Ryuta Terada . The photosynthetic responses to PAR and temperature including chilling-light stress on the heteromorphic life history stages of a brown alga, Cladosiphon okamuranus (Chordariaceae) from Ryukyu Islands, Japan . Phycological Research66 ( 3 ) 209 - 217 2018.7Reviewed International journal

Erik E. Sotka, Aaron W. Baumgardner, Paige M. Bippus, Christophe Destombe, Elizabeth A. Duermit, Hikaru Endo, Ben A. Flanagan, Mits Kamiya, Lauren E. Lees, Courtney J. Murren, Masahiro Nakaoka, Sarah J. Shainker, Allan E. Strand, Ryuta Terada, Myriam Valero, Florian Weinberger, Stacy A. Krueger-Hadfield . Combining niche shift and population genetic analyses predicts rapid phenotypic evolution during invasion . Evolutionary Applications11 ( 5 ) 781 - 793 2018.6Reviewed International coauthorship International journal

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley-Blackwell

The rapid evolution of non-native species can facilitate invasion success, but recent reviews indicate that such microevolution rarely yields expansion of the climatic niche in the introduced habitats. However, because some invasions originate from a geographically restricted portion of the native species range and its climatic niche, it is possible that the frequency, direction, and magnitude of phenotypic evolution during invasion have been underestimated. We explored the utility of niche shift analyses in the red seaweed Gracilaria vermiculophylla, which expanded its range from the northeastern coastline of Japan to North America, Europe, and northwestern Africa within the last 100 years. A genetically informed climatic niche shift analysis indicates that native source populations occur in colder and highly seasonal habitats, while most non-native populations typically occur in warmer, less seasonal habitats. This climatic niche expansion predicts that non-native populations evolved greater tolerance for elevated heat conditions relative to native source populations. We assayed 935 field-collected and 325 common-garden thalli from 40 locations, and as predicted, non-native populations had greater tolerance for ecologically relevant extreme heat (40°C) than did Japanese source populations. Non-native populations also had greater tolerance for cold and low-salinity stresses relative to source populations. The importance of local adaptation to warm temperatures during invasion was reinforced by evolution of parallel clines: Populations from warmer, lower-latitude estuaries had greater heat tolerance than did populations from colder, higher-latitude estuaries in both Japan and eastern North America. We conclude that rapid evolution plays an important role in facilitating the invasion success of this and perhaps other non-native marine species. Genetically informed ecological niche analyses readily generate clear predictions of phenotypic shifts during invasions and may help to resolve debate over the frequency of niche conservatism versus rapid adaptation during invasion.

DOI： 10.1111/eva.12592

Other Link： http://onlinelibrary.wiley.com/doi/10.1111/eva.12592/abstract

Ryuta Terada, Kazuya Matsumoto, Iris Ann Borlongan, Yuki Watanabe, Gregory N. Nishihara, Hikaru Endo, Satoshi Shimada . The combined effects of PAR and temperature including the chilling-light stress on the photosynthesis of a temperate brown alga, Sargassum patens (Fucales), based on field and laboratory measurements . JOURNAL OF APPLIED PHYCOLOGY30 ( 3 ) 1893 - 1904 2018.6Reviewed International journal

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Nature

The combined effects of photosynthetically active radiation (PAR) and temperature on the photosynthesis of a temperate Japanese brown alga, Sargassum patens (Fucales), were determined by field and laboratory measurements. Underwater measurements of the natural population of this alga in Kagoshima, Japan, revealed that the effective quantum yield (I broken vertical bar (PSII) ) declined with increasing incident PAR, with minimum I broken vertical bar (PSII) occurring during noon to early afternoon. I broken vertical bar (PSII) recovered in the evening, indicating dynamic photoinhibition. In laboratory experiments, I broken vertical bar (PSII) was also negatively correlated with PAR, which decreased after 12 h of continuous exposure to 200 (low) and 1000 (high) mu mol photons m(-2) s(-1) at 8, 20, and 28 A degrees C. Maximum quantum yield (F (v) /F (m) ) at 8 A degrees C with low PAR failed to recover after 12 h of dark acclimation, suggesting the influence of low temperature in chronic photoinhibition. Photosynthesis-irradiance (P-E) curves likewise revealed lower net photosynthetic rates and photoinhibition at 8 A degrees C. Gross photosynthesis and dark respiration experiments determined over a range of temperatures (8-40 A degrees C) revealed that the maximum gross photosynthetic rate (GP (max)) occurred at 26.9 A degrees C. F (v) /F (m) after 72 h of temperature exposures was stable at 8-32 A degrees C; but it was deactivated at 36 and 40 A degrees C. This species is well-adapted to the current range of temperature in the temperate region of Japan (7-28 A degrees C). However, the combined effects of low temperature and PAR may influence algal photosynthetic efficiency and so may be limiting at the marginal region of northern distribution of this temperate species.

DOI： 10.1007/s10811-017-1344-7

Ryuta Terada, Yoshiki Nakazaki, Iris Ann Borlongan, Hikaru Endo, Gregory N. Nishihara . Desiccation effect on the PSII photochemical efficiency of cultivated Japanese Caulerpa lentillifera under the shipping package environment . Journal of Applied Phycology30 ( 4 ) 2533 - 2538 2018.3Reviewed International journal

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Netherlands

In Japan, fresh cultivated green alga, Caulerpa lentillifera (Caulerpaceae, Bryopsidales), are packed into polystyrene containers without seawater. They can stay fresh for 1 week inside the container under room temperature, suggesting a high tolerance to desiccation. This tolerance was evaluated in the present study by employing methods based on pulse amplitude modulation (PAM) fluorometry. The chronological change of the photochemical efficiency of photosystem II (PSII) of C. lentillifera in response to desiccation under conditions experienced during the commercial shipping was examined. Desiccation experiments were carried out for 2, 4, 8, and 12 days at 20 °C. Maximum quantum yields (Fv/Fm) were measured at the initial state, after each desiccation period, and after 10-min and 3, 6, and 24-h re-immersion in seawater. Fv/Fm of samples after a 2-day desiccation remained relatively high (0.78 ± 0.04 standard deviation (SD)), while those after 4- and 8-day desiccation periods decreased and yet were considered active with values greater than 0.40 following rehydration. Samples under the 12-day desiccation had the greatest decline in Fv/Fm, (0.10 ± 0.10), along with 72% critical water loss. Failure of the seaweed to recover from desiccation stress further indicates deactivation of the photosystem, which is perhaps associated with multiple cellular alterations that result at the end in a dysfunctional alga. The packaging system that makes use of polystyrene containers for thermal insulation and an absorbent sheet for moisture control may have provided an optimal environment for the seaweed to extend its “freshness” up to 1 week by maintaining photochemical efficiency.

DOI： 10.1007/s10811-018-1442-1

Jumpei Kozono, Gregory N. Nishihara, Hikaru Endo, Ryuta Terada . The interactive effects of photoinhibition and chilling stress on the photosynthesis of a freshwater red alga, Nemalionopsis tortuosa (Thoreales) from Kagoshima, Japan . Japanese Journal of Phycology66 ( 1 ) 1 - 6 2018.3Reviewed

Iris Ann Borlongan, Kazuya Matsumoto, Yoshiki Nakazaki, Natsumi Shimada, Jumpei Kozono, Gregory N. Nishihara, Satoshi Shimada, Yuki Watanabe, Ryuta Terada . Photosynthetic activity of two life history stages of Costaria costata (Laminariales, Phaeophyceae) in response to PAR and temperature gradient . Phycologia57 ( 2 ) 159 - 168 2018.3Reviewed International journal

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Allen Press

Photosynthetic responses to photosynthetically active radiation (PAR) and temperature were investigated in the macroscopic sporophyte (SPO) and microscopic gametophyte (GAM) stages of the brown alga Costaria costata from Hokkaido, Japan. Measurements of net photosynthesis, respiration rates and photochemical efficiency were carried out using dissolved oxygen sensors and a pulse amplitude-modulated fluorometer. Net photosynthesisirradiance curves of the two life history stages revealed a similarity in their light-saturated photosynthesis rates but a difference in initial slopes, with lower efficiency in oxygenic evolution for SPO than for GAM. Consequently, compensation PAR (E-c = 9 lmol photons m(-2) s(-1)) and saturation PAR (E-k = 243 lmol photons m(-2) s(-1)) of the sporophyte were higher than for the gametophyte (E-c = 1 lmol photons m(-2) s(-1); E-k = 44 lmol photons m(-2) s(-1)). This reflects the low-PAR adaptation of the microscope stage that is commonly found on the underside of rocks or in crevices where light exposure is limited. Continuous exposures to low (6 h, 100 lmol photons m(-2) s(-1)) and high PAR (1000 lmol photons m(-2) s(-1)) induced photoinhibition of photosynthesis, with larger declines in gametophyte effective quantum yields (Phi PSII). Gametophyte maximum quantum yields (F-v/F-m) also did not fully recover even after 12 h of dark acclimation, indicating photodamage. As for the temperature response in C. costata, gross photosynthesis and F-v/F-m characteristics were similar for both developmental stages, with temperature optima ranging from 14 degrees C to 22 degrees C. Their F-v/F-m and oxygenic net photosynthesis were relatively insensitive to low temperatures but declined above 24 degrees C. This may explain the disappearance of C. costata sporophytes from their habitat during summer as well as their southern distributional limit in the western Pacific.

DOI： 10.2216/17-70.1

Yuki Watanabe, Tarou Morikawa, Takayuki Mine, Yoshio Kawamura, Gregory N. Nishihara, Ryuta Terada . Chronological change and the potential of recovery on the photosynthetic efficiency of Pyropia yezoensis f. narawaensis (Bangiales) during the sporelings frozen storage treatment in the Japanese Nori cultivation . Phycological Research65 ( 4 ) 265 - 271 2017.10Reviewed International journal

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

The chronological change of photosynthetic efficiency in a frozen storage treatment of the Japanese Nori cultivation industry was examined in the cultivated red alga, Pyropia yezoensis f. narawaensis (Saga-#5 Strain, Bangiales) by using pulse-amplitude fluorometry. During the desiccation process that was conducted after the nursery cultivation season in November, the maximum quantum yield (F-v/F-m) of the gametophytic sporelings growing on the Nori-net decreased monotonically with decreasing absolute water content (AWC), and was around 0.1 at 20% AWC. During frozen storage of the Nori-net, the F-v/F-m of the frozen gametophyte was low but stable, and ranged between 0.10 +/- 0.02 SD and 0.14 +/- 0.05 SD. The magnitude of F-v/F-m for the gametophyte of the freezing treatment, after 10min and 3h of immersion in seawater, recovered quickly. After 10min and 3h of immersion, these values were 0.29 +/- 0.12 SD and 0.47 +/- 0.05 SD during the 14days of freezing treatment, and 0.15 +/- 0.02 SD and 0.29 +/- 0.04 SD after 71days of freezing treatment, and suggest that the ability to recover gradually decreased as the storage duration increased. The response of F-v/F-m from general cultivation (i.e., directly cultivated from the nursery cultivation season) and those after 47days of freezing were almost identical, suggesting that the current Nori-net frozen storage period (6 or 7weeks) was not detrimental to the gametophyte.

DOI： 10.1111/pre.12185

Narongrit Muangmai, Khanjanapaj Lewmanomont, Anchana Prathep, Ryuta Terada, Giuseppe C. Zuccarello . Gracilaria coppejansii sp nov. (Gracilariales, Rhodophyta), a new flattened species from the Andaman coast of southern Thailand . Botanica Marina60 ( 5 ) 533 - 541 2017.10Reviewed International coauthorship International journal

Language：English Publishing type：Research paper (scientific journal) Publisher：WALTER DE GRUYTER GMBH

Studies of the taxonomy and diversity of flattened Gracilaria species which occur commonly in coastal areas of Thailand are few and underestimate species richness. Recently, flattened Gracilaria plants were collected along the west coast of southern Thailand (Andaman Sea). We describe a new flattened Gracilaria species, Gracilaria coppejansii Muangmai, Lewmanomont, Prathep, Terada et Zuccarello sp. nov., from Phuket Island on the basis of comparative morphology and rbcL sequence analyses of these samples. The new species is mainly characterized by thalli with dichotomous branching, numerous proliferations on the blade margin of female gametophytes, textorii-type spermatangial conceptacles and a few nutritive filamentous cells in mature cystocarps. Morphologically, G. coppejansii most closely resembles Gracilaria textorii but differs in some morpho-anatomical characteristics of the blade and female reproductive structures. rbcL sequence analyses also clearly demonstrated that G. coppejansii was genetically distinct from other flat Gracilaria species. Gracilaria coppejansii was phylogenetically positioned close to Gracilaria lantaensis, a recently described flattened species also on the west coast of Thailand.

DOI： 10.1515/bot-2017-0028

Takeo Horiguchi, Rui Moriya, Sohail K. Pinto, Ryuta Terada . Pyramidodinium spinulosum sp nov. (Dinophyceae), a sand-dwelling non-motile dinoflagellate from the seafloor (36m deep) off Mageshima Island, Kagoshima, Japan . Phycological Research65 ( 4 ) 272 - 279 2017.10Reviewed International journal

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

A new species of benthic marine dinoflagellate, Pyramidodinium spinulosumHoriguchi, Moriya, Pinto & Terada is described from the deep (36m) seafloor off Mageshima Island, Kagoshima Prefecture, Japan in the subtropical region of the northwest Pacific. The life cycle of the dinoflagellate consists of a dominant, attached, dome-shaped, vegetative form and short-lasting, motile cell. Asexual reproduction takes place by the formation of two motile cells within each non-motile cell. The released motile cells swim only for a short period and transform directly into the dome-shaped vegetative form. The duration of the cell cycle varies and can be extremely long, ranging 5-38days under culture conditions. The non-motile cell is enclosed by a cell wall and its surface is covered with many (80-130) spines of various length. The dinoflagellate is photosynthetic and contains many (more than 50) discoidal chloroplasts. Phylogenetic analysis reveals that the dinoflagellate is closely related to the type species of the genus Pyramidodinium, P. atrofuscum which also possesses a dominant, attached, non-motile form. However, P. spinulosum can be clearly distinguished from P. atrofuscum by the cell shape (dome-shaped vs. pyramid-shaped) and surface ornamentation (spines vs. wart-like processes) of the non-motile form. Based on these morphological differences together with molecular evidence, it was concluded that this organism from a deep water sand sample should be described as a second species of the genus Pyramidodinium, P. spinulosum.

DOI： 10.1111/pre.12183

Iris Ann Borlongan, Gregory N. Nishihara, Satoshi Shimada, Ryuta Terada . Photosynthetic performance of the red alga Solieria pacifica (Solieriaceae) from two different depths in the sublittoral waters of Kagoshima, Japan . Journal of Applied Phycology 2017.7Reviewed International journal

Stacy A. Krueger-Hadfield, Nicole M. Kollars, Allan E. Strand, James E. Byers, Sarah J. Shainker, Ryuta Terada, Thomas W. Greig, Mareike Hammann, David C. Murray, Florian Weinberger, Erik E. Sotka . Genetic identification of source and likely vector of a widespread marine invader . Ecology and Evolution7 ( 12 ) 4432 - 4447 2017.6Reviewed International coauthorship International journal

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

The identification of native sources and vectors of introduced species informs their ecological and evolutionary history and may guide policies that seek to prevent future introductions. Population genetics provides a powerful set of tools to identify origins and vectors. However, these tools can mislead when the native range is poorly sampled or few molecular markers are used. Here, we traced the introduction of the Asian seaweed Gracilaria vermiculophylla (Rhodophyta) into estuaries in coastal western North America, the eastern United States, Europe, and northwestern Africa by genotyping more than 2,500 thalli from 37 native and 53 non-native sites at mitochondrial cox1 and 10 nuclear microsatellite loci. Overall, greater than 90% of introduced thalli had a genetic signature similar to thalli sampled from the coastline of northeastern Japan, strongly indicating this region served as the principal source of the invasion. Notably, northeastern Japan exported the vast majority of the oyster Crassostrea gigas during the 20th century. The preponderance of evidence suggests G. vermiculophylla may have been inadvertently introduced with C. gigas shipments and that northeastern Japan is a common source region for estuarine invaders. Each invaded coastline reflected a complex mix of direct introductions from Japan and secondary introductions from other invaded coastlines. The spread of G. vermiculophylla along each coastline was likely facilitated by aquaculture, fishing, and boating activities. Our ability to document a source region was enabled by a robust sampling of locations and loci that previous studies lacked and strong phylogeographic structure along native coastlines.

DOI： 10.1002/ece3.3001

Takeo Horiguchi, Rui Moriya, Sohail K. Pinto, Ryuta Terada . Pyramidodinium spinulosum sp. nov. (Dinophyceae), a sand-dwelling non-motile dinoflagellate from the seafloor (36 m deep) off Mageshima Island, Kagoshima, Japan . Phycological Research63 ( 3 ) 3077 - 3088 2017.6Reviewed International journal

Iris Ann Borlongan, Grevo S. Gerung, Shigeo Kawaguchi, Gregory N. Nishihara, Ryuta Terada . Thermal and PAR effects on the photosynthesis of Eucheuma denticulatum and Kappaphycus striatus (so-called Sacol strain) cultivated in shallow bottom of Bali, Indonesia . Journal of Applied Phycology29 ( 1 ) 395 - 404 2017.2Reviewed International coauthorship International journal

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Nature

Photosynthetic responses to various temperature and PAR conditions of two carrageenophytes, Eucheuma denticulatum and Kappaphycus striatus (so-called Sacol strain), cultured in shallow areas of Bali, Indonesia, were examined using dissolved oxygen measurements and pulse-amplitude-modulated (PAM) fluorometry. Net photosynthesis-irradiance (P-E) curves at 26 A degrees C revealed that the values of P (max) for E. denticulatum and K. striatus were 13.76 and 5.02 mu g O-2 g(fw) (-1) min(-1) (12.38-15.12 and 4.55-5.50 mu g O-2 g(fw) (-1) min(-1), 95 % Bayesian prediction interval (BPI)), respectively. Photoinhibition was not observed even at 1000 mu mol photons m(-2) s(-1). Gross photosynthesis and respiration characteristics over a range of temperatures (8-36 A degrees C) revealed optimum temperature for photosynthesis to be 31.1 A degrees C for E. denticulatum, and 31.6 A degrees C for K. striatus. These characteristics of photosynthesis indicate that both farmed seaweeds are well adapted to the light and temperature conditions of the cultivation site. However, studies on longer timescales for photochemical efficiency, photosynthesis, and respiration are still needed to determine their limits of tolerance. We also hypothesize that higher values of photosynthetic parameters for E. denticulatum suggest that this species is relatively superior in productivity under optimal conditions, conditional on the farming method.

DOI： 10.1007/s10811-016-0956-7

Iris Ann G. Borlongan, Grevo S. Gerung, Gregory N. Nishihara, Ryuta Terada . Light and temperature effects on photosynthetic activity of Eucheuma denticulatum and Kappaphycus alvarezii (brown and green color morphotypes) from Sulawesi Utara, Indonesia . Phycological Research65 ( 1 ) 69 - 79 2017.1Reviewed International coauthorship International journal

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

Knowledge concerning the effects of several abiotic factors on the physiology of carrageenophytes is essential both in ecological and economic standpoints, to ensure their sufficient supply for the sustainability of seaweed-based industries. This paper presents the photosynthetic characteristics of farmed carrageenophytes, Eucheuma denticulatum and Kappaphycus alvarezii [brown (BRN) and green (GRN) color morphotypes] from Sulawesi Utara (Sulawesi Island), Indonesia, as determined by examining their photosynthetic response across different temperatures and irradiances using dissolved oxygen measurements and pulse-amplitude modulated fluorometer. Net photosynthesis-irradiance (P-E) curves at 26 degrees C revealed that net photosynthetic rates of the three seaweeds gradually increased until the estimated saturation irradiances (E-k) of 58 mu mol photons m(-2) s(-1) (49-68 mu mol photons m(-2) s(-1), 95% Bayesian prediction intervals; BPI) for E. denticulatum, and 158 and 143 mu mol photons m(-2) s(-1) (134-185 and 99-203 mu mol photons m(-2) s(-1), 95% BPI) for BRN and GRN K. alvarezii, respectively; and that no photoinhibition was observed at the highest irradiance of 1000 mu mol photons m(-2) s(-1). All seaweed samples exhibited photosynthetic tolerance to high PAR as shown by their recovery in maximum quantum yields (F-v/F-m) following chronic exposures; as well as tolerance over a broad range of temperature, which is from 19 to 33 degrees C for E. denticulatum, 20-29 degrees C for BRN K. alvarezii, and 17-32 degrees C for GRN K. alvarezii. Temperature responses of these carrageenophytes indicated that they were well-adapted to the annual seawater temperatures in the cultivation site; however, they are also likely close to threshold levels for thermal inhibition, given the decline in F-v/F-m above 30 degrees C.

DOI： 10.1111/pre.12155

Sohail Keegan Pinto, Ryuta Terada, Takeo Horiguchi . Testudodinium magnum sp. nov. (Dinophyceae), a novel marine sand-dwelling dinoflagellate from subtropical Japan . Phycologia56 ( 2 ) 136 - 146 2017Reviewed International journal

Language：English Publishing type：Research paper (scientific journal) Publisher：Allen Press

A new marine benthic dinoflagellate, Testudodinium magnum sp. nov., was described from a sand sample collected on the seafloor at a depth of 35 m off Mageshima Island, Kagoshima, Japan. The dinoflagellate possessed the characteristic features of the genus Testudodinium, but was distinguished by its extremely large size and pebbled dorsal surface of the hyposome, caused by the presence of numerous nodules. The cells of this dinoflagellate possessed a dominant sessile and a rare motile form that were morphologically distinct from each other: The sessile form was larger and the small rounded episome with longitudinal furrow was completely embedded in the hyposome; the motile form was smaller and the episome was only partly embedded in the hyposome. The ultrastructural investigations revealed the presence of a large, circular, starch-sheathed pyrenoid whose matrix was traversed by randomly arranged thylakoid lamellae. The chloroplasts formed a network radiating outward from the pyrenoid. Uniquely, this dinoflagellate possessed internal props - structures that spanned the thickness of the cell and were fibrous in nature. The props were numerous and passed through organelles and cell contents. Phylogenetic analyses based on the small-subunit ribosomal DNA gene sequences placed this dinoflagellate firmly within the Testudodinium clade with high support. On the basis of the morphological features and phylogenetic analyses, we concluded that this dinoflagellate was a new species in the genus Testudodinium.

DOI： 10.2216/16-59.1

Iris Ann Borlongan, Gregory N. Nishihara, Satoshi Shimada, Ryuta Terada . Effects of temperature and PAR on the photosynthesis of Kappaphycus sp (Solieriaceae, Rhodophyta) from Okinawa, Japan, at the northern limit of native Kappaphycus distribution in the western Pacific . Phycologia56 ( 4 ) 444 - 453 2017Reviewed International journal

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Allen Press

The successful cultivation of the Japanese Kappaphycus sp. (K. striatus auctorum japonicorum) in Okinawa, Japan, requires the detailed understanding of its physiological response to environmental factors. The photosynthetic performance of this native red alga was investigated under a variety of temperature and photosynthetic active radiation (PAR) conditions by employing methods based on pulse amplitude modulation-chlorophyll fluorometry and dissolved oxygen sensors. The net photosynthesis-irradiance (P-E) curve at 24 degrees C revealed that the compensation (E-c) and saturation (E-k) irradiances were 26 [95% Bayesian prediction interval (BPI), 11-29 mu mol photons m(-2) s(-1)] and 140 (95% BPI, 98-192) mu mol photons m(-2) s(-1), respectively. No inhibition in oxygenic evolution and quantum yield was observed at the highest PAR of 1000 mu mol photons m(-2) s(-1). However, the ability of the seaweed to recover from photoinhibition was complicated following long-term PAR exposures at 18 degrees C but not at 28 degrees C. The Japanese Kappaphycus sp. showed photosynthetic optima at 17.4-29.1 degrees C, derived from the F-v/F-m and gross photosynthesis-temperature models, respectively. These characteristic results were closely related to the depth of its habitat and its northern limit of distribution in Okinawa as influenced primarily by seawater temperature. Findings of this study should be useful to the development of culture systems adapted for subtropical waters, whether for commercial purpose or for conservation of natural communities.

DOI： 10.2216/16-140.1