Unveiling the Ocean’s Secrets: A New Species of Colossal Isopod Found in the South China Sea!

The recently identified isopod species has been designated Bathynomus vaderi, in honor of the iconic Sith Lord from the Star Wars films, Darth Vader, whose helmet bears a resemblance to the head of the marine creature.

The newly identified species is part of Bathynomus, the primary scavenging isopod genus residing in tropical and temperate deep-sea environments.

Initially described in 1879 by French zoologist Alphonse Milne-Edwards, this genus encompasses nearly 20 extant and four fossil species.

These organisms are plentiful in the frigid deep waters of the Atlantic, Pacific, and Indian Oceans.

They are particularly famous due to their gigantism, with certain species attaining remarkable lengths exceeding 30 cm (11.8 inches).

Their appearance is strikingly similar to the significantly smaller common woodlouse, with which they share a familial link.

And akin to woodlice, while they may appear somewhat frightening, they pose no danger to humans.

“In the past seven years, Bathynomus has gained popularity in Vietnam as a delicacy within modern culinary trends, and some even liken it to lobsters due to the quality of its meat,” noted Peter Ng and colleagues from the National University of Singapore.

“The rising demand has led to intensified fishing activities aimed at capturing Bathynomus for the live seafood market, with specimens offered live in eateries (in chilled containers without water) or within cold-water tanks in larger restaurants.”

“Thanks to the seafood trade, we were able to gather a substantial series of specimens collected by Vietnamese fishermen in Quy Nhon City, all sourced from the South China Sea.”

“While a majority of these samples can be classified as Bathynomus jamesi, six specimens exhibited unique characteristics, including a differently shaped clypeal region and pleotelson structure, along with a notably shorter appendix masculina.”

Dubbed Bathynomus vaderi, the new species can grow up to 32.5 cm (12.8 inches) in length and exceed 1 kg in weight.

This marine organism is recognized only from the waters surrounding the Spratly Islands in Vietnam.

It is the fourth Bathynomus species characterized by upwardly curved spines and the second supergiant within the South China Sea.

“The discovery of such an unusual species as Bathynomus vaderi in Vietnam underscores how limited our knowledge is regarding the deep-sea ecosystem,” the researchers stated.

“That a species of this magnitude could have remained hidden for so long serves as a reminder of the extensive research still required to understand what exists in Southeast Asian waters.”

“There is a pressing necessity to enhance our comprehension of deep-sea biodiversity as humanity increasingly seeks to exploit this habitat for fisheries, oil and gas, and even minerals.”

“The sustainable harvesting of giant isopods merely adds to the numerous challenges we encounter. The first step is to ascertain what life inhabits these depths.”

The team’s study was published in the journal ZooKeys.

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P.K.L. Ng et al. 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; doi: 10.3897/zookeys.1223.139335