Tag: crustacean

The Sith Lord of the Sea: Supergiant Isopod in the WoRMS’ Top 10 Marine Species of 2025

The supergiant deep-sea isopod of the genus Bathynomus makes it to WoRMS Top 10 Marine Species of 2025.

What is now celebrated globally as Taxonomist Appreciation Day began in 2013. 19 March was declared by Dr. Terry McGlynn – a researcher and professor at California State University, Dominguez Hills – as a new holiday to highlight the extraordinary importance of taxonomy and taxonomist scientists to research in other fields.

To celebrate the scientists who classify, define, and name all things living, the World Register of Marine Species (WoRMS) has issued its Top 10 Marine Species of 2025, honouring the discoveries in marine biology throughout the past year.

Last year saw fascinating discoveries in the world of marine life. And today, we are super excited to share with you the species that made it to the Top 10 this year, first published in Pensoft’s open-access journal ZooKeys.

How are these lists compiled? It is a rigorous process, where WoRMS first invites all their editors to nominate their favourites, and then asks a small committee of taxonomists and data managers to provide their votes.

Now, without further ado, join us into the Dark Side to find out exactly why and how this particular species turned up at the top.

The Supergiant Isopod

The head of Bathynomus vaderi. Image by Nguyen Thanh Son

Meet Bathynomus vaderi, a supergiant isopod belonging to the genus Bathynomus. Species from this genus can reach more than 30 cm in length and are known in Vietnam as bọ biển or “sea bugs.” Bathynomus vaderi marks the first record of such a species in Vietnamese waters.

As you might have guessed, the moniker vaderi is inspired by the appearance of its head, which closely resembles the distinctive and iconic helmet of Darth Vader, the most famous character of Star Wars.

From the Market to the Lab

  • Prof. Peter Ng examining giant isopods from a seafood market in Hanoi, October 2024. Photo by Nguyen Thanh Son
  • Dr. Conni Sidabalok examining individuals of Bathynomus vaderi at Lee Kong Chian Natural History Museum, Singapore. Photo by Rene Ong

The story of how it was found is quite compelling. In contrast to the traditional image of deep-sea expeditions, Bathynomus vaderi was obtained from local sellers where the isopods are fished.

In March 2022, staff from Hanoi University purchased four giant isopod individuals from Quy Nhơn City and sent two of them to Peter Ng from the National University of Singapore for identification. Subsequently, this sparked an international collaboration between Ng, Conni M. Sidabalok (National Research and Innovation Agency, Indonesia), and Nguyen Thanh Son (Vietnam National University). Together, this expert team studied the specimens and confirmed they had discovered a species new to science.

Video by Kyle Hill on YouTube.

A Deep-Sea Delicacy

Giant isopods like Bathynomus vaderi have become an expensive delicacy in Vietnam. Until 2017, local fishermen only sold them as low-priced bycatch, but in recent years, the media has drawn public attention to this unusual seafood. Some even claim it is more delicious than lobster, the “king of seafood.”

The Importance of the Find

News story by Margherita Bassi via the Smithsonian magazine.

This discovery is a reminder of just how much we still don’t know about the vast deep-sea environment. If such a supergiant isopod could remain hidden for so long, it speaks to the extraordinary amount of work still needed to uncover the rich biodiversity of Southeast Asian waters – work that depends on the combined efforts of researchers and taxonomists, whose contributions are at the frontline of conservation.

The celebration is not over; we invite you to explore the Pensoft-published species that have previously made it to the WoRMS Top 10 and revisit the ocean’s most fascinating discoveries:

Original study:

Ng PKL, Sidabalok CM, Nguyen TS (2025) A new species of supergiant Bathynomus A. Milne-Edwards, 1879 (Crustacea, Isopoda, Cirolanidae) from Vietnam, with notes on the taxonomy of Bathynomus jamesi Kou, Chen & Li, 2017. ZooKeys 1223: 289-310. https://doi.org/10.3897/zookeys.1223.139335

Sir Elton John is the inspiration behind the name of a new coral reef crustacean species

While exploring the remote coral reefs of Raja Ampat in Indonesia, Dr. James Thomas from the Halmos College of Natural Sciences and Oceanography, Florida, and his colleagues from Naturalis Natural History museum in the Netherlands, stumbled across a small but extraordinary crustacean living inside another reef invertebrate in a commensal association (without causing any harm, nor benefit to its host).

In his amazement to the amphipod’s unusual form, Dr. Thomas called it L. eltoni after musician and actor Sir Elton John. The research is available in the open access journal ZooKeys.

“I named the species in honour of Sir Elton John because I have listened to his music in my lab during my entire scientific career,” the lead author explains. “So, when this unusual crustacean with a greatly enlarged appendage appeared under my microscope after a day of collecting, an image of the shoes Elton John wore as the Pinball Wizard came to mind.”

Taxonomists, scientists who study and name new species, have the choice to pick names that are relevant to locations, features of the animal, or people the scientist admires.

In an interesting twist L. eltoni is now reported from Hawaiian waters as an invasive species. “Several years ago I was contacted by scientists from the Bishop Museum in Honolulu to help identify an unusual amphipod they had collected,” said Dr. Thomas. It proved to be the same species as the one from Indonesia. The most likely scenario for its introduction into Hawaiian waters was as a hitchhiker inside its host sponge or tunicate that was attached to a large floating drydock transported to Hawaii from Subic Bay, Philippines. Recent studies by Dr. Thomas in the Philippines during a California Academy of Science expedition in 2014 have shown this new species is also found there.

Marine animals can have unknown effects when transported to other ecosystems where they can compete with native species. In most cases these “invasions” go unnoticed. However, because scientists at the Bishop Museum had established a baseline of species over the years the presence of this invasive amphipod was quickly noted.

“Such studies show the importance of regular environmental monitoring, especially in tropical environments,” commented the scientist. He also pointed out that even though their tiny size, crustaceans such as L. eltoni provide crucial information about reef health.

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Original source

Thomas J. D. (2015) Leucothoe eltoni sp. n., a new species of commensal leucothoid amphipod from coral reefs in Raja Ampat, Indonesia (Crustacea, Amphipoda). ZooKeys 518: 51-66. doi: 10.3897/zookeys.518.9340