Giant Darth Vader sea beetle discovered off Vietnam's coast

Giant Darth Vader sea beetle discovered off Vietnam's coast

Scientists have identified a new "supergiant" species of deep-sea crab after purchasing crustaceans from fishermen and restaurants in Vietnam to study the creatures' growing popularity as a local delicacy.

Discovery of Bathynomus vaderi

The one now asBathynomus vaderiThe deep-sea crab got its name because researchers noticed that its head resembled one of the helmets worn by iconic “Star Wars” villain Darth Vader. The scientists documented the newly discovered species on Tuesday in the ZooKeys magazine and confirmed that certain elements of the body structure ofB. vaderidiffer significantly from other Bathynomus samples in the South China Sea.

Characteristics of supergiants

The super giants among deep sea crustaceans, includingB. vaderi, belong to the isopod family, characterized by their hard, protective exoskeleton and seven pairs of legs. The largest specimen examined in the study weighed more than 1 kilogram and measured 32.5 centimeters, whichB. vaderimaking it one of the largest known isopods in the world.

The body structure of Bathynomus crustaceans is comparable to many shallow-water cirolanids - the isopod family to which they belong - but these deep-sea animals have increased significantly in size, according to Dr. Conni Sidabalok, a co-author of the study and researcher at the National Research and Innovation Agency in Indonesia.

Most isopods are incredibly small, typically measuring less than 2.5 centimeters. These size differences make the discovery of such a large specimen particularly remarkable, explained Dr. Lanna Cheng, professor emeritus of marine biology at the University of California, San Diego, who was not involved in the study.

The identification of a new species

Fishermen, theB. vaderiwere engaged in deep-sea trawling in the South China Sea about 50 nautical miles off the town of Quy Nhon in southern Vietnam, west of the Spratly Islands.

B. vaderilives near the bottom and feeds on dead animals, which helps recycle nutrients in the deep sea food chain. Sidabalok noted that this species' massive bodies could aid its survival in the ocean depths or provide a competitive advantage over other scavengers.

Currently, only 11 known “supergiant” and nine “giant” species of Bathynomus are documented, with several awaiting formal description.B. vaderiis only the second recorded supergiant isopod species discovered in the South China Sea.

The distinction ofB. vaderiHowever, identifying other species was a laborious process for the research team because these crabs live in such deep waters.

Unique characteristics of B. vaderi

Unlike other known supergiant isopodsB. vaderia unique feature: The final segment of the hind legs tapers at the end and curves slightly backwards, the study found.

About the uniqueness ofB. vaderiTo confirm this, Sidabalok and her colleagues examined samples of related species from museum collections in various countries and worked with other experts. In addition, the researchers analyzed the DNA ofB. vaderi, but the lack of genetic data for many Bathynomus species presented additional identification challenges.

The threat of overfishing

In recent years, other Bathynomus species, such asB. jamesi, has become a delicacy in Vietnam, with its meat often compared to that of lobster. The researchers report that some specimens were sold for up to 2 million Vietnamese dong in 2017. However, as popularity increased, prices fell as the crustaceans were caught in larger numbers.

At the beginning of 2024, 1- to 2-kilogram specimens were sold for about 1 million Vietnamese dong. With the discovery ofB. vaderiScientists like Sidabalok and Cheng raise concerns about the possible integration of this species into global seafood markets.

BADTonomus are known for their slow reproduction. These supershelled crabs produce only a small number of eggs - in just a few hundred - which hatch as miniature versions of the adults. Sidabalok noted that this slow reproductive rate makes them particularly vulnerable to overfishing.

"These animals don't grow very quickly, and if they become a very unusual and sought-after item, we risk wiping them out," Cheng warned.

The research team believes thatB. vaderialso occurs outside Vietnam's coastal waters in other parts of the South China Sea, but discovering more species at these depths will take time.

Sidabalok hopes this research paves the way for further study of Bathynomus populations and can help fishermen develop more sustainable practices. “If we get the opportunity, we would like to conduct further surveys and perhaps work with scientists from the region to find out what lives there,” Sidabalok added. “There is still so much to learn and discover.”