Giant ‘Darth Vader’ sea bug discovered off the coast of Vietnam

Deep beneath the waves of the South China Sea, researchers have uncovered a creature straight out of a sci-fi fantasy: a “supergiant” sea bug with a striking resemblance to one of cinema’s most iconic villains. The newly identified species, named Bathynomus vaderi, owes its moniker to its uncanny likeness to the helmet worn by Darth Vader in Star Wars. Officially described in the journal ZooKeys, this massive deep-sea dweller is now one of the largest known isopods in the world.

Scientists stumbled upon the species while studying the growing popularity of Bathynomus as a delicacy in Vietnam. Purchasing specimens from fishermen and local restaurants, they noticed unique features that set B. vaderi apart from other known species. The crustacean boasts a hard exoskeleton, seven pairs of legs, and a body structure that evolved for life in the ocean’s abyss. The largest specimen documented weighed more than 1 kilogram (2.2 pounds) and measured 32.5 centimeters (12.8 inches) long—a far cry from the typical isopod, which is often less than 2.5 centimeters (1 inch) in size.

Dr. Conni Sidabalok, a researcher with the National Research and Innovation Agency in Indonesia and coauthor of the study, explained that B. vaderi’s massive size likely provides a competitive edge in the deep sea. These bottom-dwelling scavengers play a critical role in recycling nutrients by feeding on dead animals. However, their size is not their only distinguishing feature. Unlike other supergiant isopods, B. vaderi has a unique trait: the last segment of its back legs narrows and curves slightly backward.

The species was discovered during deep-sea trawling operations about 50 nautical miles off the coast of Quy Nhon, Vietnam. Researchers noted that distinguishing B. vaderi from other Bathynomus species was no easy task, given the inaccessibility of their deep-sea habitat. Currently, there are only 11 known “supergiant” and nine “giant” Bathynomus species, with several still awaiting formal description.

While the discovery adds to the scientific understanding of deep-sea biodiversity, it also raises concerns. Bathynomus species, including B. jamesi, have gained popularity as a delicacy in Vietnam, with their flesh often compared to lobster. In 2017, specimens fetched as much as 2 million Vietnamese dong ($80), though prices have since dropped as the creatures became more widely available. By early 2024, 1-to-2-kilogram (2.2-to-4.4-pound) specimens were selling for around 1 million Vietnamese dong ($40).

This growing demand poses a serious threat to Bathynomus populations. These crustaceans are known for their slow reproduction, producing only a few hundred eggs at a time. “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,” said Dr. Lanna Cheng, professor emeritus of marine biology at the University of California, San Diego, who was not involved in the study.

The research team believes B. vaderi may inhabit other parts of the South China Sea beyond Vietnam’s waters, but uncovering additional species in such depths will require time and effort. Sidabalok expressed hope that the study will inspire further research and encourage sustainable fishing practices.

“There is still so much to learn and discover,” she said. “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.”