🌅 These Giant Deep-Sea Roly-Polies Can Go Years Without Eating

SOURCE

Yuan et al. (2026)

WHAT TO KNOW

• Researchers at the Chinese Academy of Sciences found certain species of giant deep-sea isopods—essentially football-sized roly-polies lurking at the bottom of the ocean—can go more than five years without eating thanks to a pair of biological quirks that allow them to store energy and reduce expenditure unlike most other animals. The discovery offers new insights into how evolutionary changes develop and how some organisms adapt to survive extreme environments.

WHY IT MATTERS

• The researchers examined specimens of two giant isopod species that live at different depths: Bathynomus jamesi from nearly 3,000 feet below the ocean surface and B. doederleini from around 1,000 feet deep. The team found the deepest-dwelling isopods have an enormous stomach that takes up around two-thirds of their body—proportionally much larger than other giant species—which the researchers believe acts as a huge storage container for food. Genetic analysis also found both species have a gene called ND1, which appears to slow the production of energy, helping the animals endure prolonged periods without eating. The researchers believe the gene once belonged to a bacterium that lived inside the isopods' stomachs, eventually becoming part of their own genome around 16 million years ago through a process known as horizontal gene transfer.

CONNECT THE DOTS

• Giant deep-sea isopods are distant cousins of garden-variety roly-polies on land (i.e., pill bugs), much like supergiant amphipods are related to common shrimp and tiny “sand fleas” found on beaches. Experts theorize that gigantism is so widespread among deep-sea creatures because the deep sea is functionally similar to an island. The isolation and lack of resources, competition, and predators found on islands leads many small-bodied animals to evolve larger bodies, like Galápagos tortoises. Scientists believe several deep-sea groups follow the same pattern.