By Julianna Bragg, CNN
Researchers said they named a newfound species "Bathynomus vaderi" because the supergiant sea bug's head resembles Darth Vader's helmet. Photo: Nguyen Thanh Son via CNN Newsource
Scientists have newly identified a "supergiant" sea bug species after purchasing crustaceans from fishermen and restaurants in Vietnam to study the growing popularity of the creatures as a local delicacy.
The deep-sea critter, now called Bathynomus vaderi, got its name after researchers noticed its head shared a resemblance to the helmet worn by iconic Star Wars villain Darth Vader.
The scientists officially described the new-found species on Tuesday in the journal ZooKeys, confirming that some elements of B. vaderi's body structure differed greatly from other Bathynomus specimens found in the South China Sea.
Supergiant sea bugs - including B. vaderi - were members of the isopod family, characterised by their hard, protective exoskeleton and seven pairs of legs.
The largest specimen in the study weighed more than 1kg and measured 32.5cm long, making B. vaderi one of the world's largest known isopods.
The overall body structure of Bathynomus crustaceans was similar to many shallow-water cirolanids - the isopod family it belongs to - but these deep-sea creatures had evolved to be significantly larger, according to study co-author Dr Conni Sidabalok, a researcher with the National Research and Innovation Agency in Indonesia.
Most isopods were incredibly small, typically measuring less than 2.5cm in length.
This disparity in size made the discovery of such a huge specimen particularly remarkable, Dr Lanna Cheng said, professor emeritus of marine biology at the University of California, San Diego, who was not involved in the study.
Identifying a species that's new to science
Fishermen who caught B. vaderi were deep-sea trawling in the South China Sea about 50 nautical miles offshore of the city of Quy Nhon in south-central Vietnam, which is west of the Spratly Islands.
B. vaderi are bottom dwellers that feed on dead animals, recycling nutrients as part of the deep-sea food chain, Sidabalok said.
Study co-author Dr Conni Sidabalok, of the National Research and Innovation Agency in Indonesia, examining Bathynomus vaderi specimens at Lee Kong Chian Natural History Museum in Singapore. Photo: CNN Newsource/Rene Ong
She noted that Bathynomus' massive size may aid its survival in the ocean's abyss or provide a competitive advantage over other scavengers.
Currently, there are only 11 known "supergiant" and nine "giant" Bathynomus species, with several awaiting formal description, according to the study.
B. vaderi was only the second recorded supergiant isopod species discovered in the South China Sea.
However, because these crustaceans inhabit such deep waters, distinguishing B. vaderi from other species was a laborious process for the research team.
Unlike other recorded supergiant isopods, B. vaderi possesses a unique feature: The last segment of its back legs narrows at the end and curves slightly backward, according to the study.
To confirm B. vaderi's uniqueness, Sidabalok and her colleagues examined specimens of related species from museum collections across various countries and collaborated with other experts.
In addition, the researchers analysed the DNA of B. vaderi, but the lack of genetic data for many Bathynomus species presented additional challenges in the identification process.
Vietnamese delicacy vulnerable to overfishing
In recent years, other Bathynomus species, such as B. jamesi, had become a delicacy in Vietnam, with their flesh often compared to that of lobster, according to the study.
As Bathynomus grew in popularity, in 2017 some specimens were sold for up to 2 million Vietnamese dong ($80), researchers wrote.
However, as fishermen caught and sold more Bathynomus, prices dropped because the sea bugs became more widely available.
Study co-author Dr Thanh Son Nguyen, a researcher at Vietnam National University, holding B. jamesi in October 2024. The species of isopod is also found in the coastal waters of Vietnam, and this specimen weighs 2.6 kilograms (5.8 pounds). Photo: CNN Newsource/ Peter Ng
By early 2024, 1-to-2kg specimens were being sold for around 1 million Vietnamese dong ($40), the study noted.
With the discovery of B. vaderi, scientists such as Sidabalok and Cheng had raised concerns about its potential integration into global seafood markets.
Bathynomus were known for their slow reproduction.
These supergiant crustaceans produce a small number of eggs - only in the hundreds - which hatch as miniature versions of the adults, Sidabalok said.
She added that this slow reproduction rate made them especially vulnerable to overfishing.
"These [creatures] don't grow very fast, and if they become a very unusual and sought-after item, we may eat them out of existence," Cheng said.
The research team believed B. vaderi exists beyond Vietnam's coastal waters in other parts of the South China Sea, but uncovering other species in these depths would take time.
Sidabalok said she hoped this research would pave the way for further research into Bathynomus populations and help fishermen develop more sustainable practices.
"If we get the chance, we would like to do more surveys and perhaps work with scientists in the region to ascertain what is living there," Sidabalok said.
"There is still so much to learn and discover."
- CNN
