Tag: jellyfish

New Michelin Star Jellyfish Discovered in Japanese Aquaria

Malagazzia michelin is only the second species of its genus to be found in Japanese waters.

Researchers have reported the discovery of a new species of jellyfish, Malagazzia michelin, marking only the second species of its genus ever found in Japanese waters. Led by Takato Izumi of Fukuyama University, the discovery was a collaborative effort between marine biologists and staff from several prominent institutions, including the Tsuruoka City Kamo Aquarium and the Saikai National Park Kuju-kushima Aquarium. The full study is published in the open-access journal ZooKeys.

First spotted in the shallow waters of Nagasaki and Yamaguchi Prefectures, the Malagazzia michelin jellyfish has subsequently been cultured and studied in captivity, providing scientists with a complete look at its entire life cycle from polyp to adult.

Sampling localities of Malagazzia michelin. A. Tabira and Sasebo, Nagasaki Pref. (indicated by black stars); B. Katasoe-ga-hama, Yamaguchi Pref. (by grey star). (Image credit: Izumi et al.).

A Unique Marine Resident

Malagazzia michelin is a small aquatic invertebrate characterised by a hemispherical, transparent umbrella that typically grows to between 12 and 20 millimeters in diameter. While it shares the four-lipped mouth and linear gonads typical of its genus, it is easily distinguished by a peculiar feature: enigmatic brown spots that resemble tiny oil droplets scattered across its reproductive organs and central stomach. DNA analysis has confirmed its status as a unique species, which is distinct from other known members of the Malagazzia family.

Enlarged view of the structures of living Malagazzia michelin. A, B. Closed lips; C. Open lips; D. Tentacles and tentacular bulbs; E–G. Gonads; F. Mature female; G. Mature male. Scale bar: 0.1 mm. (Image credit: Izumi et al.).

The species has been aptly named Malagazzia michelin as a playful nod to the famous Michelin Guide. As the jellyfish matures, the number of its distinctive brown spots increases, a process that researchers likened to a restaurant earning more “stars” for its quality. This celestial theme is also reflected in its new Japanese common name, ama-no-gawa-kurage (Milky Way jellyfish), which compares the white gonads and twinkling brown spots to a starry galaxy.

External view of the living medusae of Malagazzia michelin. A. Lateral view; B. Oral view; C. Lateral view of Kuju-kushima 3 with lighting; D–F. Kuju-kushima 1; D. Aboral view; E. Sketch from aboral side; F. Lateral view. Scale bar: 5 mm. (Image credit: Izumi et al.).
Polyps and juvenile–young medusae of Malagazzia michelin. A. Development of juvenile medusae; B–E. Polyps. Scale bar: 1 mm (thick); 200 µm (slender). (Photo credit: Izumi et al.).

Navigating the Confusion of Common Names

The formal scientific description of M. michelin addresses an interesting challenge in Japanese marine biology: the risk of common names. In Japan, ornamental jellyfish are often given descriptive common names, such as “salmon-roe laodicean jellyfish” (tsubuiri-sujiko-yawara-kurage), long before they are scientifically identified. This can lead to confusion – M. michelin, for instance, was previously misidentified in field guides as a member of the Laodicea genus, which is not closely related. Researchers emphasise that formal taxonomic work is essential to ensure that the biodiversity displayed in aquaria is accurately documented.

The discovery of Malagazzia michelin demonstrates the significant role that aquariums play as centres for scientific research and biodiversity discovery. By strengthening ties between public exhibitions and taxonomic research, scientists continue to bring the ocean’s most stellar species to light.

Original source:

Izumi T, Ikeda S, Nozoe Y, Goto S, Imamura N, Kinoshita T, Uchida H, Hamatsu Y, Akiyama H, Okuizumi K (2026) Discoveries from ornamental jellyfish in aquaria—description of Malagazzia michelin sp. nov. (Cnidaria, Hydrozoa, Leptothecata), second species of the genus from Japan. ZooKeys 1268: 13-32. https://doi.org/10.3897/zookeys.1268.173354

For more articles on zoology, visit the ZooKeys website and follow the journal on BlueSky and Facebook.

From an amateur nature video to a unique study on Antarctic jellyfish

Video, posted online by an amateur videographer that explored life under the sea ice in Antarctica, resulted in a unique taxonomic study on Antarctic jellyfish and an image-based training set for machine learning.

Sometimes, scientific discoveries emerge from the strangest turns of events.

It all started in 2018, when Dr. Emiliano Cimoli, postdoctoral researcher at the University of Tasmania, joined a field campaign to McMurdo Sound in the Ross Sea, Antarctica – to study not jellyfish, but rather the algal communities that thrive beneath the ice. 

This crystal-like comb jelly species, Callianira cristata, has been reported for the first time in the Ross Sea by the team of researchers. Photo by Dr. Emiliano Cimoli

“These algae are like the plants of the under-ice world and are very important for the Antarctic food chain,” Dr. Cimoli says.  The research team he was part of focused on the development of new sensing technologies to monitor these algal communities (e.g. optical techniques and chemical microsensors).

“We usually have a nice large tent to be able to work and operate such instruments in the harsh Antarctic environment. The cool part is that inside this tent, we have a massive 2 x 2 m hole in the sea ice that allows us to deploy these instruments to the under-ice world.”

It’s kind of like a magic portal to another world filled with mysterious and wondrous jellyfish-like creatures that live down there.

Besides working as an engineer and remote sensing scientist, Dr. Cimoli is also a passionate amateur nature and wildlife photographer and videographer, and in his free time he decided to document all sightings of these creatures with his camera. The researcher used a combination of macro photography equipment and a set of light sources, along with underwater robots for filming underwater. 

This brownish-orange comb jelly of the genus Beroe is likely one of the five undescribed species characterized by the team of researchers. Photo by Dr. Emiliano Cimoli

“Finally, I ended up having a massive amount of jellyfish footage, did not know what to do with it, then lockdown hit and suddenly I found myself working on a trippy video composition of all these creatures,” he adds.

The value of his video was soon picked up by biologist Dr. Gerlien Verhaegen, postdoctoral researcher at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC):

“When I came across Emiliano’s video, I was amazed by the image quality of his underwater footage. You could clearly distinguish some key morphological features.” Unlike hard-bodied animals, the fragile body of jellyfishes and comb jellies (i.e. “sea gooseberries”) are easily destroyed when sampled with nets, which is why photography and videography of specimens are crucial to describing them taxonomically.

“Life Beneath the Ice”, a short musical film about light and life beneath the Antarctic sea-ice by Dr. Emiliano Cimoli

The two postdocs soon joined forces to produce a collaborative study. 

“I think I underestimated the time needed to produce a jellyfish taxonomic paper,” laughs Dr. Verhaegen. “Most of the original descriptions of Antarctic jellies date back to the so-called Heroic Age of Antarctic Exploration in the early 20th century, and are written in English, French, and German. Furthermore, due to the high-water content of jellies, it is extremely difficult to fix and preserve them in formalin or ethanol. We therefore could not compare our specimens to physical specimens preserved in museums but had to rely on the century old descriptions and drawings. Luckily, we were in good hands with my project host, Dr. Dhugal Lindsay, senior scientist at JAMSTEC, a jellyfish taxonomist expert, and last author of our paper”.

Filming creatures in their natural environment can yield valuable information on their trophic interactions with other organisms. For example, this picture of a Diplulmaris antarctica jellyfish shows it feeds on comb jellies, with a Beroe present in its stomach, whereas numerous hyperiid amphipods (small parasitic crustaceans) are observed scattered around on the bell of the jellyfish. Photo by Dr. Emiliano Cimoli

Despite the small geographical and temporal scale of this study, which was published in the open-access Biodiversity Data Journal, a total of 12 species were reported, with two jellyfish and three comb jellies likely representing undescribed species.

Besides revealing new morphological traits for every species, including some behavior and trophic traits, this study was also the first to include a training image set for video annotation of Antarctic jellyfish through machine learning. 

“Machine learning is being applied to numerous fields nowadays, from voice recognition software and translation through to detection of typhoon formation,” comments Dr. Lindsay.

“In marine biology, annotating species from underwater videos can be both time-consuming and financially costly, with very few experts able to give names to the high diversity of species invariably encountered. Machine learning techniques could help solve these issues by enabling automatic first-pass annotation of videos. However, taxonomically accurate image-based datasets are needed to train these learning algorithms, and this study is a valuable first step.”

Watch the video “Life Beneath the Ice” by Dr. Emiliano Cimoli on YouTube and Vimeo.

Original source

Verhaegen, G., Cimoli, E., & Lindsay, D. J. (2021). Life beneath the ice: jellyfish and ctenophores from the Ross Sea, Antarctica, with an image- based training set for machine learning. Biodiversity Data Journal, 9, e69374. https://doi.org/10.3897/BDJ.9.e69374