Bathynomus vaderi is a species of giant deep-sea isopod in the family Cirolanidae, commonly referred to as a giant isopod. It is a marine crustacean inhabiting deep benthic environments of the Indo-Pacific, primarily off the coast of Vietnam near the Spratly Islands. The genus name Bathynomus derives from the Greek bathys meaning “deep” and nomos meaning “dweller” or “inhabitant,” reflecting its abyssal habitat, while the species epithet vaderi references the fictional character Darth Vader due to the distinctive shape of its cephalon (head), which resembles the character’s helmet.

Bathynomus vaderi is a large scavenging isopod adapted to deep-sea conditions, possessing a heavily armored exoskeleton and the ability to withstand high pressure and long periods without food. Bathynomus vaderi has recently entered niche culinary markets in parts of Vietnam, Taiwan and Japan, where deep-sea trawling has occasionally brought them to shore. Giant isopods are prepared by steaming or boiling, with the flesh described as similar in flavor to crab or lobster but with a firmer texture.

Bathynomus vaderi contains compounds typical of decapod and isopod crustaceans. These include omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), astaxanthin, chitin, and free amino acids such as glycine and glutamate that contribute to umami flavor. As with other deep-sea crustaceans, potential accumulation of heavy metals may be a consideration depending on habitat.