Category: Lab Updates

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From the beginning of February to the end of April, the IMS Lab has the pleasure of being joined by Mr. Nicolo Ferraris from Wageningen University. During his 3-month exchange program, Nicolo will be assisting on the HABs research project.

Statement from Nicolo:

Hi! I’m Nicolo, an Italian MSc Biology student from Wageningen University & Research in the Netherlands, where I specialized in Molecular Ecology. I just finished my thesis on investigating sex determination in invasive lionfish (Pterois miles), which got me hooked on combining lab work with bioinformatics. I’ve always been really interested in applied molecular biology, especially next-generation sequencing technologies like Nanopore for biodiversity monitoring.

I arrived in Sendai on February 1st and have been loving the experience so far. The people in the lab are great and made me feel right at home since day one. I’ve been helping Sang with organizing samples, joined him for field sampling out in Onagawa (which was amazing!), and have been assisting with eDNA extractions and Planktoscope processing. During the Nanopore training workshop in mid-February, I got hands-on experience with library prep and running the GridION for environmental DNA samples across different locations and gene regions. After the workshop, I noticed the bioinformatics workflow was a bit over-complicated, so I introduced the team to EPI2ME, Oxford Nanopore’s platform, and gave everyone a quick tutorial on how to use it. Since then, I’ve been working through the sequenced samples and generating preliminary taxonomic results for our HAB species and broader plankton communities. Outside of lab work, I’ve been enjoying joking around with the friends I made here, playing basketball and volleyball, indulging in the excellent food, and exploring Sendai!

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New Research: A comparative molecular study of rhizostome jellyfishes from Japan reveals variability in Symbiodiniaceae taxon associations and cassiosome production.

Led by Kei Chloe Tan , this study dives deep into the complex world of Rhizostomeae that play massive roles in Asian ecology and industry.

What makes these jellies unique?

Rhizostome jellyfishes are unlike your average medusa. They don’t have long, trailing tentacles neither other structures at the eadg of theyr bell; they have eight highly branched oral arms, along which there are suctorial minimouth orifices.

Our study focused on three main goals:

  • Identity: Using DNA barcoding to accurately identify species in Japanese waters.
  • Partnership: Mapping which types of algae live inside which jellyfish.
  • The Sting: Identifying which species produce cassiosomes—the “mucus grenades” responsible for the mysterious “stinging water” syndrome.

Key Discoveries

  • A New Neighbor: We discovered that Cassiopea (Upside-down jellyfish) found in Kagoshima likely represents a new, undescribed species.
  • Symbiotic Flexibility: We found that these jellyfishes are “plastic” in their partnerships, meaning the same species of jellyfish can host different types of algae (Symbiodinium, Cladocopium, or Durusdinium) depending on the individual.
  • The “Grenade” Evolution: We confirmed that cassiosome production is a unique trait of the suborder Kolpophorae. Interestingly, we found that young jellies might not produce them until they reach a certain developmental stage.

“This research provides a baseline for understanding how jellyfish and algae co-evolve, helping us manage coastal ecosystems and the jellyfish fisheries that are so vital to the region.” — Chloe Tan, Lead Author

Lab Work in Action

This paper wasn’t just about sequences; it combined advanced molecular techniques with classic microscopy.

  • Tandem DNA Amplification: Chloe developed a new method to simultaneously sequence the DNA of both the jellyfish host and its tiny algal residents.
  • Microscopy: We captured high-resolution images of the cassiosomes—clusters of stinging cells (nematocysts) with algae at their core—proving exactly how these “contactless stings” work.

Read the Full Paper

Interested in the molecular data or the high-resolution phylogenetic trees? You can find the full study here:

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カツオノエボシは1種ではなかった：5種への再分類と新種「ミカヅキノエボシ」の命名 執筆：彩恵 りり

サイエンスライターの彩恵りり氏が、カツオノエボシ属（Physalia属）が5種に再分類された最新の研究について詳しく解説してくださいました。これら新種のうち1種の発見に当研究室が貢献したことを、大変光栄に思います。

[彩恵りり氏による解説記事はこちら]

[当研究室のオリジナル論文はこちら]

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Nikkei reported on Mikazuki no Eboshi: 宮城県で新種のクラゲ、伊達政宗にちなんで命名　東北大学

Our lab’s discovery was featured in a Nikkei article. The piece focused on the computer simulation used to estimate the period and travel path of the specimen, as it originated from a different region than the discovery site:

コンピューターを使ったシミュレーション（模擬実験）の結果、神奈川県沖の相模湾などから海流に乗って運ばれた可能性があると分かった。研究成果をまとめた論文は学術誌「フロンティアズ・オブ・マリン・サイエンス」に掲載された。

Find the original material at:

Find the original scientific paper here:

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New jellyfish species “Mikazuki no Eboshi” first confirmed in Tohoku

tank

By: 官庁通信デジタル _ KANCHO TSUSHIN DIGITAL

A group led by Professor Cheryl Ames of Tohoku University has discovered a new species of jellyfish, the “Mikazuki no Eboshi” This is the first time that a highly venomous species of jellyfish, a relative of the Portuguese man-of-war, has been found in Tohoku. They analyze that one of the reasons for its discovery is the abnormal fluctuations in ocean conditions in recent years.

The Portuguese man-of-war lives in tropical and temperate climates. In Japan, it is found from Okinawa to Sagami Bay, but has not been officially confirmed along Japan’s northern coast until now. The crescent-shaped crest of the helmet worn by Date Masamune, a military commander active in the Tohoku region, is the origin of the name.

The Mikazuki fish was collected after being washed up on Gamo Beach in Sendai City, Miyagi Prefecture. It is speculated that the northward movement of the Kuroshio Current carried this species, which lives in southern Japan, to Tohoku. Ocean current simulations suggest that it takes about 30 days for the fish to travel from Sagami Bay to Sendai Bay, and 45 days to reach the coast of Aomori.

The group commented that “this study provides important insights into understanding the movement and dispersal of marine organisms due to climate change,” and added, “Changes in the appearance and distribution of jellyfish have the potential to affect not only ecosystems but also people’s lives and safety, so we need to carefully monitor their trends.”

Find the original material at: 官庁通信デジタル

Find the original scientific paper here

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NHK – Coverage – Tohoku University research group names new species after Date Masamune

NHK broadcast the findings of our laboratory. We are exceptionally proud of our team’s achievement and delighted by the public interest generated by our research.

The broadcast provided a concise overview of the discovery and the underlying shift in marine currents that led the specimens to be washed ashore in Sendai Bay.

As Professor Ames stated:

“The discovery of this new species was incredibly exciting and a fortunate find, but it also serves as an indicator that the species is migrating north due to climate change.”

You can access the full NHK coverage and video on their website by clicking the icon below:

And you can find the complete scientific paper here:

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A new species of Portuguese man-of-war discoverd for the first time in the tohoku region – Named “Mikazuki no Eboshi” after Date Masamune

Mikazuki no Ebochi

2025 | Press Releases and Research Results

Tohoku University just released a press release show casing the most recent lab discovery at Sendai Bay. The before-mentioned “Mikazuki no Eboshi”

The emergence of this species may be related to changes in the marine environment caused by climate change, such as the northward shift of the Kuroshio Current and rising sea temperatures. The northward movement of poisonous species not only changes the ecosystem, but also requires caution when swimming in the sea.

This is the first record of the Portuguese man-of-war genus in the Tohoku region. Furthermore, particle tracking simulations revealed that the northward shift of the Kuroshio Current and rising sea temperatures may be related to the emergence of this species. The observation of the Mikazuki no Eboshi provides important evidence that climate change is affecting the distribution of marine life.

You can find the Scientific paper here:

You can find the full press relese here:

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Unlocking the Mysteries of the Wild Ocean

field-ready eDNA

Dr. Cheryl Ames is pioneering accessible and rapid methods for tracking marine biodiversity, with a special focus on box jellyfish and shifting octopus populations.

She uses Environmental DNA (eDNA), a technique that involves analyzing trace amounts of DNA left behind by species in the ocean water. By employing a field-ready eDNA pipeline that includes portable equipment like the Bento Lab, Dr. Ames and her students can conduct on-site PCR and quickly assess species presence, making data generation reliable even in remote areas.

This method allows researchers to generate data for critical issues, such as predicting the presence of highly venomous jellyfish for public safety, and providing sustainable fishing advice to local communities facing dramatic shifts in octopus populations following the 2011 tsunami.

Dr. Ames is committed to making advanced DNA analysis affordable and accessible, ensuring the next generation of scientists can apply these crucial techniques in any environment, regardless of laboratory resources.

This post is based on the article published by Bento Lab.

Find the full content at theyr web site

field-ready eDNA

Find eDNA related work done by the lab here