Discover the immediate dilemmas facing the Enoshima Aquarium—and what this means for their highly successful Portuguese Man-of-War exhibit.
Following the big splash made by the scientific discoveries originating from our lab, the established understanding of Physalia (the Portuguese Man-of-War) has been revolutionized. Research, which included the recent identification of Physalia mikazuki by our lab, now shows that what was once thought to be a single species first expanded to four and, with our lab’s subsequent discovery, grew to five distinct species in just over three months.
Opening what promises to be an amazing series in the Enoshima Aquarium Trainer’s Journal, Trainer Yamamoto presents a critical series of questions that highlight the practical impact of new taxonomy:
“Will we need to change the scientific names listed on our fish display boards and exhibits? Which species does the Japanese common name ‘Katsuo-no-Eboshi’ actually refer to? Since it is famous as a ‘highly venomous creature,’ are all five species equally dangerous?”
We are closely monitoring the developments at the Enoshima Aquarium and anxiously awaiting the answers to their questions.
It’s amazing to see the far-reaching impact of new and relevant scientific discoveries. You can find the full original post in the Enoshima Aquarium Trainer’s Journal here:
New, Venomous Portuguese Man-of-War Discovered in Japan’s North: Physalia mikazuki
This new species, named Physalia mikazuki (“crescent helmet man-o-war”) in honor of the samurai lord Date Masamune, marks the northernmost recorded presence of the Physalia genus to date, with specimens collected off the coast of northeastern Japan (Sendai Bay).
A student-led research team at Tohoku University (greatly formed by our lab) has formally identified a previously unknown species of the venomous siphonophore, Physalia —commonly known as the Portuguese man-of-war.
Key Scientific Findings:
New Species Identification: Through detailed morphological examination and genetic analysis, the team confirmed that P. mikazuki is genetically distinct from its tropical relatives, specifically Physalia utriculus, which was previously believed to be the only species of the genus inhabiting Japanese waters.
Climate-Driven Range Extension: The appearance of P. mikazuki in the colder waters of the Tohoku region suggests a significant shift in marine distribution. Ocean surface current simulations confirmed that the northward extension of the Kuroshio Current, combined with unusually high sea-surface temperatures, likely transported the colonies to Sendai Bay.
Ecological Significance: The discovery provides direct evidence that climate-related changes in ocean circulation are actively reshaping the distribution of marine species, highlighting the urgency of coastal observation.
The research not only adds a new species to the world’s taxonomic records but also underscores the immediate impact of climate change on ocean ecosystems, influencing where even dangerous marine life can drift and thrive.
In a rare marine encounter, researchers in Japan have uncovered a previously unidentified species of Portuguese man-of-war, Physalia mikazuki, off the coast of northeastern Japan. This marks the first time such a venomous jellyfish has been documented so far north in the country, with experts tying its arrival to warmer waters and changing currents.
A new species of Portuguese man o’ war has been discovered floating in the waters of northeast Japan. Spotted by a student-led research group, the discovery marks a species that has never been seen before in the area, raising questions about shifting distributions of marine creatures due to the effects of climate change.
The lab work is making a big impact in the media. We are proud to display the media coverage here and you can access the complete story on the IFLScience website.
Our recent research paper, detailing the discovery of a new venomous jellyfish species in Japan, has captured international media attention, with outlets highlighting the fascinating cultural connection of its name and its critical implications for marine science.
The discovery, published in Frontiers in Marine Science, confirms the existence of Physalia mikazuki sp. nov.—a new type of Portuguese Man-of-War found unexpectedly far north in Japan’s Tohoku region.
A Name Worthy of a Warrior
The media coverage, including articles from Tohoku University, Asia Research News, and ScienceDaily, emphasized the unique story behind the new species’ name. The jellyfish was named P. mikazuki (“crescent helmet man-o-war”) as an homage to the legendary samurai warrior and feudal lord of Sendai, Date Masamune, who was famous for the crescent moon (mikazuki) adorning his helmet.
This culturally significant name drew attention to a serious scientific finding: the species’ arrival in the temperate Tohoku region is a direct result of marine ecosystem change.
Climate Change Drives Species North
The research, led by a team including Cheryl Lewis Ames, Chanikarn Yongstar, Kei Chloe Tan, and Ayane Totsu, suggests that warming coastal waters and the northward shift of the Kuroshio Current are pushing tropical species into previously untouched temperate zones. The study used DNA analysis and particle simulation modeling (as highlighted by the coverage) to confirm the species is distinct and to track its probable drift path from warmer waters.
This finding serves as a powerful indicator of how climate change is rapidly altering the global distribution of marine organisms, necessitating increased monitoring to ensure coastal safety and ecological understanding.
Tohoku University stands at the forefront of tackling some of the most pressing global challenges, particularly those related to our planet’s changing marine ecosystems. The Tohoku University Integrated Report 2024 highlights groundbreaking research and initiatives that aim to understand and mitigate the impacts of environmental shifts on ocean life and beyond.
Unraveling Marine Ecosystems with Environmental DNA
At the heart of marine research is Professor Cheryl Ames, Unit Leader/Principal Investigator at the Advanced Institute for Marine Ecosystem Change (WPI-AIMEC) and Professor at the Graduate School of Agricultural Science. Professor Ames’s research, which notably began with her fascination for jellyfish, has evolved into broader marine organismal studies utilizing environmental DNA (eDNA) analysis.
eDNA, collected from the environment (like seawater), provides a snapshot of all organisms inhabiting an ecosystem at a specific time, even revealing the environmental burden imposed by human activities. Professor Ames has developed a compact, portable eDNA detection kit, significantly reducing the time and cost associated with estimating jellyfish distribution over wide areas. This versatile kit can also be adapted to extract biological data from various other marine organisms.
Collaborations are key to this research. Professor Ames’s unit works with octopus fishers and wholesale auction centers in Minamisanriku, Miyagi, collecting eDNA to aid resource management in Shizugawa Bay and contribute to food sustainability. Further efforts are underway in Okinawa to develop rapid eDNA tests, crucial for regions where jellyfish damage impacts human health and tourism
Addressing Earth’s Changes and Shaping Ocean Life
WPI-AIMEC was established with a strong sense of urgency to decipher the mechanisms behind ocean warming and connect this understanding to projection models. The institute acknowledges the increasing vulnerability of marine ecosystems to rapid changes, suchando as rising global ocean temperatures and fluctuating ocean currents. Incidents like the mass outbreak of venomous Portuguese man-of-war in Miyagi Prefecture underscore the unprecedented phenomena occurring in our oceans.
Understanding the ocean requires an integrated approach, encompassing physics, chemistry, biology, and ecosystems, rather than isolated disciplinary studies. Tohoku University facilitates multidisciplinary research, bringing together diverse specializations to explore connections between sub-disciplines and gain a better understanding of the overall mechanisms of the ocean environment. The ultimate goal is to understand the relationship between the ocean and ecosystems, providing options for actions to build a sustainable society capable of adapting to environmental and ecological changes.
WPI-AIMEC aims to leverage AI to integrate various data types, enhancing our understanding of marine environments and the interactions between marine ecosystems and human society. The establishment of a centralized repository for valuable marine samples and their metadata (including eDNA sequences and images) is also a key initiative to invigorate marine ecology research. Outreach efforts include workshops for researchers and engaging elementary school students in eDNA sample collection to foster ocean conservation.
Tohoku University’s commitment to pioneering research in marine science, exemplified by Professor Ames’s work and the WPI-AIMEC initiative, is vital for a sustainable future.
The national university in the northeastern Japan prefecture of Miyagi is set to be formally selected as early as fiscal 2024 as a recipient of annual financial support for up to 25 years from fiscal 2024, starting with around 10 billion yen ($69 million) in the initial year.
Under the new Universities for International Research Excellence program, the grants will be paid out of profits generated from a 10 trillion yen fund.
Tohoku University has been rated highly for its large number of research paper citations, and measures to strengthen its research capabilities and reform its management, the ministry said.
Our team at Tohoku University, led by Associate Professor Alyne Delaney, just launched SEAQUEST – a vital research project tackling the complex challenges facing fisheries in Japan’s Tohoku region since the 2011 earthquake.
We’re blending cutting-edge science, like eDNA and AI for species distribution modeling, with traditional socio-ecological concepts like satoumi and umigyo. This holistic approach helps us understand why some fisheries have declined while others increased, especially with changing ocean conditions and parasitic outbreaks.
SEAQUEST emphasizes community-based citizen science, collecting crucial data from simple water samples. We’re working closely with diverse local and international stakeholders, including fishing communities (even women fishers!), tourism, and industry partners.
Our goal? To combine local ecological knowledge with scientific methods to foster true social and environmental sustainability. Co-Principal Investigators Professor Cheryl Ames and Associate Professor Toyonobu Fujii are key to this interdisciplinary effort.
