Marine Botany Lab Achievements in 2025

These articles present the 2025 annual research achievements of the Marine Botany Laboratory at Kagoshima University, Japan. As we reflect on the past year, we extend our heartfelt gratitude to all the students, colleagues, co-authors, and contributors who helped make this year a success.

 

Articles

1. Nozomi Shiiba, Momochika Kumagai, Hikaru Endo, Tomoki Tsuruta, Keisuke Nishikawa, Yoshiki Morimoto 2025. Anti-inflammatory diterpenoids from the brown alga Dictyota coriacea. Bioscience, Biotechnology, and Biochemistry 89 (2): 224–231 https://doi.org/10.1093/bbb/zbae163 (Online: 24 January 2025).

 

2. 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 2025. Exploring the impact of the widely introduced Pacific oyster Magallana gigas on the dispersal of Bonamia (Haplosporida): A global snapshot. Diseases of Aquatic Organisms 161: 39–46 https://doi.org/10.3354/dao03834 (Online: 6 February 2025)

 

3. Ryuta Terada 2025. Significant decline in the seaweed and seagrass communities in Kagoshima, Kyushu Island, Japan. Jeju Journal of Island Sciences 2 (1): 20–26 https://doi.org/10.23264/JJIS.2025.2.1.020 https://www.jjis.or.kr/articles/article/M4xR/ (Online: 28 February 2025)

 

4. Masahiro Suzuki, Ryuta Terada 2025. DNA-based floristic survey of red algae (Rhodophyta) growing in the mesophotic coral ecosystems (MCEs) offshore of Tanegashima Island, northern Ryukyu Archipelago, Japan. PLoS ONE 20 (3): e0316067 https://doi.org/10.1371/journal.pone.0316067 (Online: 10 March 2025)

 

5. 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 Schwindt, Åsa Strand, Richard Taylor, Ryuta Terada, Martin Thiel, Takefumi Yorisue, Danielle Zacherl, Allan E. Strand 2025. The genetic legacy of a global marine invader. Proceedings of the National Academy of Sciences of the United States of America 122 (15) e2418730122 https://doi.org/10.1073/pnas.2418730122 (Online: 7 April 2025) 

 

6. Masahiro Suzuki, Chiyuki Zemba, Ryuta Terada 2025. Solieria latifolia sp. nov. and S. yoshidae sp. nov. (Solieriaceae, Rhodophyta) from offshore Tanegashima Island, Japan. Phycologia 64 (2): 137–149 https://doi.org/10.1080/00318884.2025.2494493 (Online: 12 May 2025; Issue: 1 July 2025)

 

7. Ryuta Terada, Kotaro Makino, Gregory N. Nishihara 2025. 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 Phycology 37 (4): 2753–2768 https://doi.org/10.1007/s10811-025-03528-7 (Online: 16 May 2025; Issue: 1 August 2025)

 

8. Ryuta Terada, Aoi Shindo, Hikari Moriyama, Narumi Shimboku, Gregory N. Nishihara 2025. The effects of desiccation and salinity gradients in the photochemical efficiency of a mesophotic green alga, Ryuguphycus kuaweuweu (Ulvaceae) from Kagoshima, Japan. Phycological Research 73 (4): 294–300 https://doi.org/10.1111/pre.70010 (Online: 27 August 2025; Issue: 1 October 2025)

 

9. Ayaka Horikoshi, Hikaru Endo, Masakazu N. Aoki, Yukio Agatsuma (2025) High recruitment of the sea urchin Mesocentrotus nudus following the 2011 Tohoku Tsunami, Japan. Marine Ecology Progress Series 770: 99–112 https://doi.org/10.3354/meps14944 (Online: 2 October 2025)

 

10. Christophe Vieira, Shingo Akita, Masahiro Suzuki, Ryuta Terada, Takeaki Hanyuda, Satoshi Shimada, Shinya Uwai. Hiroshi Kawai 2025. A taxonomic sudoku: Resolving the long-standing puzzle of Japanese Dictyoteae (Dictyotales, Phaeophyceae) with new records and biogeographic insights. Journal of Phycology 61 (5): 1457–1485 https://doi.org/10.1111/jpy.70084 (Online: 10 October 2025: Issue: 23 October 2025)

 

11. Taiju Kitayama, Masahiro Suzuki, Ryuta Terada 2025. 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, Botany 51 (4): 1–9 https://doi.org/10.50826/bnmnsbot.51.4_127 (Issue: 25 November 2025)

12. Ryuta Terada, Takuzo Abe, Shingo Akita, Mitsunobu Kamiya, Hiroshi Kawai, Akira Kurashima, Chikako Nagasato, Yoshihiko Sakanishi, Hiromori Shimabukuro, Haruka Suzuki, Jiro Tanaka, Shinya Uwai, Yuki Watanabe, Ryoko Ueno, Misuzu Aoki 2026. Significant changes in seaweed community structure revealed by a nationwide long-term monitoring survey in Japan “Monitoring-Site 1000” over the past 15 years (2008–2022). Phycological Research 74 (1): 39–56 https://doi.org/10.1111/pre.70019 (Online: 8 December 2025; Issue: January 2026)

13. Ryuta Terada, Masahiro Suzuki, Taiju Kitayama, Yoichi Sato, Gregory N. Nishihara 2026. 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 38: https://doi.org/10.1007/s10811-025-03736-1 (Online: 22  December 2025)

 

In press

14.  Kosuke Uchimura, Yushin Fujimoto, Hikaru Endo, Momochika Kumagai 2026. Marine terpenoids with antimelanogenic activity from the brown alga Dictyopteris polypodioides in B16 melanoma cells. Bioscience, Biotechnology, and Biochemistry 90 (2): 166–172 https://doi.org/10.1093/bbb/zbaf167 (February 2026)

 

New article: First record of Ulva kanagawae from Ogasawara Islands, Japan

Please take a look at our new article reporting the first record of Ulva kanagawae V. Carneiro, N. T. Martins & Cassano from Chichi-jima in the Ogasawara (Bonin) Islands, Japan. This alga was described as a new species in 2023, but the type locality was São Paulo, Brazil. Our finding represents the first record of this species from the Pacific Ocean. Because the biogeographic connection between Ogasawara and São Paulo remains unclear, we are very excited to see future records that may further clarify the distribution of this alga.

Kitayama, Suzuki, Terada 2025.
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, Botany 51 (4): 127–135
DOI: 10.50826/bnmnsbot.51.4_127

https://www.jstage.jst.go.jp/article/bnmnsbot/51/4/51_127/_article/-char/ja

Congratulations to Dr. Taiju Kitayama, National Museum of Nature and Science, on his great work!  

New article: Japanese Dictyoteae (Dictyotales) with new records and biogeographic insights.

Please take a look at our new article on the reassessment of the taxonomic status of Dictyoteae algae from Japan. Congratulations to Dr. Christophe Vieira on this excellent work!

Christophe Vieira, Shingo Akita, Masahiro Suzuki, Ryuta Terada, Takeaki Hanyuda, Satoshi Shimada, Shinya Uwai. Hiroshi Kawai 2025.

A taxonomic sudoku: Resolving the long-standing puzzle of Japanese Dictyoteae (Dictyotales, Phaeophyceae) with new records and biogeographic insights. 

 

Journal of Phycology 61: 1457-1485

 

DOI: 10.1111/jpy.70084

https://onlinelibrary.wiley.com/doi/10.1111/jpy.70084

  

Dictyota haenyeosa

New article: Ryuguphycus kuaweuweu

Please take a look at our new article on the effects of desiccation and salinity gradients on the photochemical efficiency of a mesophotic green alga, Ryuguphycus kuaweuweu.

Terada, Shindo, Moriyama, Shimboku, Nishihara 2025

The effects of desiccation and salinity gradients in the photochemical efficiency of a mesophotic green alga, Ryuguphycus kuaweuweu (Ulvaceae) from Kagoshima, Japan. Phycological Research

https://doi.org/10.1111/pre.70010

https://onlinelibrary.wiley.com/doi/10.1111/pre.70010

 

Ryuguphycus kuaweuweu

 

Second day of the Special Workshop on Making Seaweed Specimens for Elementary School Kids

On the second day of the seaweed specimen workshop for elementary school children, July 26, participants placed labels on the sheets and created their own herbarium specimens of 30 species, which were compiled into exsiccatae. The exsiccatae included field guide pages for each species, specially prepared by us for the workshop. 

This workshop was supported as part of the outreach programs under the Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS).

 

Special Workshop on Making Seaweed Specimens for Elementary School Kids

We held a special workshop on making seaweed specimens for elementary school children as part of their summer holiday activities. On the first day, July 19, participants pressed samples of 30 species collected during our field surveys, including edible species such as Nori (Pyropia) and Wakame (Undaria). After pressing the samples for the specimens, they also made seaweed bookmarks.

Next weekend, after the samples have fully dried, we will hold the second day of the workshop, during which participants will make herbarium specimens to complete their own exsiccatae. This workshop was conducted with funding from KAKENHI, provided by the Japan Society for the Promotion of Science (JSPS).

 

 

 

New article: Sheathia yedoensis sp. nov.

Please take a look at our new article on a newly discovered species of the genus Sheathia from near the Imperial Palace in Tokyo. It was a collaborative study with the National Museum of Nature and Science, Tokyo.

 

Kitayama and Suzuki 2024 

Sheathia yedoensis, a New Species of the Freshwater Red Alga (Batrachospermaceae, Rhodophyta) from Kitanomaru Park, Adjacent to the Imperial Palace, Tokyo, Japan

Bulletin of the National Museum of Nature and Science. Series B, Botany 

https://doi.org/10.50826/bnmnsbot.50.4_131 

New article: Thorea okadae

Our new article, which elucidates the photosynthetic response of the freshwater red alga Thorea okadae to environmental gradients of temperature, irradiance, desiccation, and salinity, was recently published in the Journal of Applied Phycology. Thorea okadae is a freshwater red alga distributed in the southern and western parts of Japan and is listed as an endangered species by the Ministry of the Environment of Japan. We believe that the insights presented in the article will contribute to a better understanding of the conservation of this species.

Terada, Makino, & Nishihara 2025. 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 Phycology, 37. https://doi.org/10.1007/s10811-025-03528-7

https://link.springer.com/article/10.1007/s10811-025-03528-7 

Thorea okadae

New article: Solieria latifolia sp. nov. and S. yoshidae sp. nov. (Solieriaceae, Rhodophyta) from offshore Tanegashima Island

Please take a look at our new article on two newly discovered species of the genus Solieria from offshore Tanegashima Island. It was published on May 12, 2025, in Phycologia, the official journal of the International Phycological Society.

Suzuki, Zemba, & Terada. 2025. Solieria latifolia sp. nov. and S. yoshidae sp. nov. (Solieriaceae, Rhodophyta) from offshore Tanegashima Island, Japan. Phycologia, 64. DOI:10.1080/00318884.2025.2494493
https://www.tandfonline.com/doi/full/10.1080/00318884.2025.2494493
 

In recent years, we have focused on species diversity and environmental adaptations in Mesophotic Coral Ecosystems (MCEs—ecosystems found at depths greater than 30 m) around offshore Tanegashima Island, and have published a series of related articles. The species name Solieria yoshidae was dedicated to the late Dr. Tadao Yoshida (1933–2024), Professor Emeritus of Hokkaido University, who was a specialist in the taxonomy of Solieria.

https://www.kagoshima-u.ac.jp/topics/2025/05/post-2326.html

Research voyage of the T/S Nansei-Maru, Kagoshima University

The Marine Botany Lab and Kagoshima City Aquarium participated in a research voyage aboard the T/S Nansei-Maru of Kagoshima University, conducting a deep subtidal algal survey off the coast of Tanegashima Island in the northern Ryukyu Islands. The weather and sea conditions were calm, and we successfully returned to Kagoshima today. This survey was conducted as part of a training voyage for university students in the Faculty of Fisheries.

 

Nationwide long-term monitoring of algal communities

As part of a collaboration between our lab and the algal lab at Kobe University, Professor Terada and an MSc student participated in field surveys for the nationwide long-term monitoring of algal communities, which was conducted by Kobe University. During two surveys—at Awajishima Island and Takeno—dense communities of Ecklonia and Sargassum spp. were confirmed.

Kobe University Marine Site at Awajishima Island

Ecklonia cava

Takeno Site

Sargassum spp.

 

MB Laboratory Seminar

We had an MB Laboratory seminar at the beginning of the spring semester. As it was the first seminar of the term, Dr. Terada and Endo presented their recent research topics. The seminar will be held every two weeks until September, during which students will present their progress reports and introduce recently published articles.

 

 

Asian Pacific Phycological Association (APPA) Regional Forum in Shandong 2025

Professor Ryuta Terada of the Marine Botany Lab attended the Asian Pacific Phycological Association (APPA) Regional Meeting in Rongcheng, Shandong Province, China, from April 21 to 23, 2025. During the meeting, studies on kelps and other valuable species were presented, and constructive discussions took place. Rongcheng City is one of China’s most productive regions for Saccharina japonica cultivation. 

The next APPA regional meeting will be held in Thailand in 2026. 

New article: The genetic legacy of a global marine invader (PNAS)

Please take a look at a newly published article on the introduction of the Pacific oyster, as well as other species that were transported with it to various regions. The article is now available in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

This study was led by Professors Erik Sotka and Allan Strand of the Grice Marine Laboratory, College of Charleston, USA, and was conducted through international collaboration, including contributions from our laboratory.

Congratulations to Erik, Allan, and all the other outstanding coauthors involved!

Erik E. Sotka et al. 2025. The genetic legacy of a global marine invader. Proceedings of the National Academy of Sciences of the United States of America 122 (15) e2418730122

DOI: 10.1073/pnas.2418730122

https://www.pnas.org/doi/10.1073/pnas.2418730122

Special Exhibition at Kagoshima City Aquarium: The World of Marine Algae

As the opening event of the special exhibition The World of Marine Algae, a workshop on making marine algae herbarium specimens was held at Kagoshima City Aquarium in Kagoshima. Twelve elementary and junior high school students attended. The students created herbarium specimens of twenty-four species of marine algae collected from various locations in Kagoshima Prefecture.

 

 

 

 

 

New article: DNA-based floristic survey of red algae (Rhodophyta) growing in the mesophotic coral ecosystems (MCEs) offshore of Tanegashima Island

 Please take a look at our latest article on the DNA-based floristic survey of red algae (Rhodophyta) in the mesophotic coral ecosystems (MCEs) offshore of Tanegashima Island, Japan. 

 

This study presents the first comprehensive catalog of red algae comprising the sublittoral marine flora (deeper than 30 m) around offshore Tanegashima Island 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 identified a total of 129 species, including nine newly recognized in Japan.

 

Suzuki, M, and Terada, R 2025. DNA-based floristic survey of red algae (Rhodophyta) growing in the mesophotic coral ecosystems (MCEs) offshore of Tanegashima Island, northern Ryukyu Archipelago, Japan. PLoS ONE 20(3): e0316067 DOI: 10.1371/journal.pone.0316067

 

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0316067 

Spring has come!

Spring has come!
As spring arrives, the time of the lowest daily low tide shifts from nighttime to daytime, making intertidal algae surveys easier to conduct on the rocky shore. Yesterday, we conducted a survey at Nishikata Beach, Satsuma-Sendai City, which faces the East China Sea. Notably, Pyropia suborbiculata, Grateloupia asiatica, and Gloiopeltis furcata were abundant on the intertidal rocks.

OBITUARY: DR. TADAO YOSHIDA (July 8, 1933 – November 11, 2024) 追悼 吉田忠生 博士（北海道大学名誉教授）

OBITUARY: DR. TADAO YOSHIDA (July 8, 1933 – November 11, 2024)

With great sadness, we announce the passing of Dr. Tadao Yoshida, Professor Emeritus at Hokkaido University, Japan. He was a renowned member of the Japanese phycological community, celebrated for his groundbreaking research on the taxonomy of algae, particularly Sargassum and other species. His seminal work, Marine Algae of Japan (Yoshida 1998), cataloged all recognized species of marine algae in the region. Not only marine algae, but he also studied the taxonomy of some freshwater red algae including Nemalionopsis and Thorea. 

 

Dr. Yoshida earned his BSc, MSc, and Ph.D. at the Faculty of Agriculture, Kyushu University, obtaining his Ph.D degree (in Agriculture) in 1964. His research and teaching careers spanned three esteemed institutions: Kyushu University (1962), the Tohoku National Fisheries Research Institute (1962–1968), and the Faculty of Science, Hokkaido University (1968–1997). During his time at Hokkaido University, he also earned another Ph.D. degree (in Science).

 

An active member of the Japanese Society of Phycology for many years, Dr. Yoshida served as its President from 1995 to 1996. In recognition of his significant and long-standing contributions to phycology, he was honored with the Japanese Society of Phycology’s Yamada Award in 2016.

 

His name is commemorated in several algal species in recognition of his contributions to phycology:

 

Genus Yoshidaphycus Mikami, 1992

Yoshidaphycus ciliatus (Okamura) Mikami 1992

 

Sargassum yoshidae G.C.Trono 1994

 

Gelidium yoshidae G.H.Boo & R.Terada 2016

 

Dr. Ryuta Terada, head of the Laboratory of Marine Botany at Kagoshima University, had a longstanding history of communication with Dr. Yoshida, which began when Terada met him as a student at Hokkaido University in the 1990s. Their collaborative research continued even after Yoshida’s retirement from Hokkaido University in 1997. Together, they conducted a government survey on the marine algal flora and endangered freshwater algae in Kyushu and the Ryukyu Islands during the 2000s, which included the discovery of a new species, Sargassum ryukyuense, from Okinawa and Amami (Shimabukuro et al. 2008). Dr. Masahiro Suzuki, an Assistant Professor at the same laboratory, also collaborated with Dr. Yoshida, resulting in the publication of The Checklist of Marine Algae of Japan in 2015.

 

The members of the Laboratory of Marine Botany at Kagoshima University are deeply grateful for Dr. Yoshida’s invaluable service and contributions.

 

May he rest in peace.

 

Yoshidaphycus ciliatus (Okamura) Mikami 1992

 

論文：分布南限の褐藻アントクメ：消失したと思われていた鹿児島県馬毛島沖での再確認

研究室の新しい論文が植物研究雑誌より刊行されました。

 

寺田竜太 2024．分布南限の褐藻アントクメ：消失したと思われていた鹿児島県馬毛島沖での再確認．

植物研究雑誌99 (4): 273–279

DOI: 10.51033/jjapbot.ID0211（刊行日：2024年8月20日）

 

Ryuta Terada 2024. 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 Botany 99 (4): 273–279

DOI: 10.51033/jjapbot.ID0211 (Issue: 20 August 2024)

 

https://www.jstage.jst.go.jp/article/jjapbot/99/4/99_ID0211/_article/-char/ja

 

褐藻アントクメEcklonia radicosa（コンブ目）の標本や記録における分布南限は，種子島の西方に位置する馬毛島沖ですが，1971年の標本以降生育が確認されないままでいました。本種は馬毛島周辺海域から消失した可能性が考えられてきましたが，2023年10月7日の調査航海で実施したドレッジ調査において，本種の生育が改めて確認されました。

 

植物研究雑誌の論文のダウンロードは，刊行から2年間は雑誌購読者に限られています（2年以上を経たものはオープンアクセス）。論文に関心のある方は，お気軽に我々にお問い合わせください。なお，植物研究雑誌は2025年の刊行100周年に併せ，電子媒体のみによる完全オープンアクセスに移行するそうです。

A special workshop on making seaweed specimens for elementary school kids

We held a special workshop on making seaweed specimens for elementary school kids as an event during their summer holidays. On the first day, July 20, we pressed samples of 30 species collected during our field surveys, including some edible species like Nori and Wakame. Next weekend, after fully drying the samples, we will have the second day of the workshop, making herbarium specimens to complete their own exsiccatae. This workshop was conducted with funding from KAKENHI, provided by the Japan Society for the Promotion of Science (JSPS).

 

Second Jeju International Island Symposium

Professor Ryuta Terada, the head of the Marine Botany Laboratory, was invited to the 2nd Jeju International Island Symposium as one of the speakers. The symposium was held from July 9th to 11th in Jeju City, Korea. He presented the status of the nationwide long-term monitoring survey known as "Monitoring-Site 1000" in Japan over the past 15 years. As Jeju Island and Kyushu Island are very close, with a distance of around 200 km between them, we believe our concerns about the degradation of seaweed communities observed in Kyushu may be helpful in considering the possibility of future changes in seaweed communities on Jeju Island. We express our thanks to the organizing committee of this symposium for inviting him to this wonderful opportunity.

 http://amkijeju.re.kr/98