A new species of giant marine insect named after Darth Vader

Giant isopods of the genus Bathynomus, which can reach more than 30 cm in length, are known as bọ biển or “sea bugs” in Vietnam. For the first time, one of these species was described in Vietnamese waters and named Bathynomus vaderi. The name “vaderi” is inspired by the appearance of his head, which closely resembles the distinctive and iconic helmet of Darth Vader, Star Wars’ most famous Sith Lord.

Bathynomus vaderi belongs to a group known as “supergiants”, reaching a length of 32.5 cm and weighing more than a kilogram. So far, this new species has only been found near the Spratly Islands in Vietnam, but further research will likely confirm its presence in other parts of the South China Sea.

Giant isopods like Bathynomus vaderi have become an expensive delicacy in Vietnam. Until 2017, local fishermen sold them only as a low-cost accessory product, but in recent years the media has drawn public attention to these unusual seafood. Some go so far as to claim that it is more delicious than lobster, the “king of seafood”.

These animals were fished commercially by trawlers operating in various deep-water parts of Biển Đông (East Sea, Vietnamese part of the South China Sea) and off the provinces of the south-central coastal region of the Vietnam.

Over the past five years, it has become common to see them sold alive in some seafood markets in Hanoi, Hồ Chí Minh City and Đà Nẵng City. Some outlets and restaurants even advertise the sale of these “sea bugs” online on various social media platforms.

In March 2022, Hanoi University staff purchased four giant isopods from the city of Quy Nhơn and sent two of them to Peter Ng of the Lee Kong Chian Museum of Natural History at the National University of Singapore for identification.

Peter Ng has a very active crustacean laboratory in Singapore and has worked on deep-sea fauna from many parts of Asia. He then co-opted Conni M. Sidabalok of the National Research and Innovation Agency of Indonesia, who had described Bathynomus from South Java with him.

Together with resident shellfish researcher Nguyen Thanh Son of Vietnam National University, they studied the specimens. In early 2023, they realized they held specimens of a previously undescribed species.

Now they have published their findings in the open access journal ZooKeys.

The discovery of a species as strange as Bathynomus vaderi in Vietnam shows how little we understand the deep-sea environment. The fact that such a large species has been able to remain hidden for so long reminds us how much work we still have to do to discover what lives in Southeast Asian waters.

There is an urgent need to better understand our deep-sea biodiversity, as humans increasingly strive to exploit this habitat for fishing, oil and gas, and even minerals. Sustainable fishing for giant isopods only adds to the many challenges we face. And the first step is to know what lives there.