Deep-Sea Isopods Use Giant Stomachs and Borrowed Genes to Survive Years Without Food

Deep-sea isopods of the genus *Bathynomus* live at about 300 m (B. doederleini) and 900 m (B. jamesi) where food arrives only as sporadic “snowflakes” of organic matter, yet they can persist for over five years without a new meal. Their stomach occupies about two-thirds of the body cavity, acting as an internal “food warehouse” that stores a large intake as a paste-like reserve. Metabolically they operate in a “standby mode,” using energy at a reduced rate. Metagenomic analysis found *Chlamydiae* bacteria linked to lipid storage and the ND1 gene—originally from a symbiotic bacterium—now integrated via horizontal gene transfer. ND1 regulates mitochondrial activity, functioning as a temperature-dependent metabolic switch. Laboratory insertion of ND1 into zebrafish, nematodes and human 293T cells increased starvation survival by 37 % under cold conditions that simulate the deep sea.

Deep-sea marine animal can go more than 5 years without eating, combining physical adaptations and genetic mechanisms to survive in environments with extreme food scarcity; meet the Bathynomus.

The study was led by Jianbo Yuan, professor at the Institute of Oceanology, Chinese Academy of Sciences, with contributions from Jianhai Xiang (Institute of Oceanology), Kahou Chu (Chinese University of Hong Kong) and Li Xinzheng. It combined genomic, physiological, behavioral, morphological and metagenomic approaches.

Reuters

The authors describe the enlarged stomach as a critical “energy warehouse” that releases nutrients slowly while the animal remains in “standby mode,” and attribute the low metabolic demand to both the anatomy and the ND1 gene, which they call a metabolic switch that fine-tunes energy use, especially at deep-sea temperatures. The team emphasizes that the findings illustrate an evolutionary strategy merging horizontal gene transfer with epigenetic optimization to balance growth and survival under extreme resource limitation.

Deep-sea marine animal can go more than 5 years without eating, combining physical adaptations and genetic mechanisms to survive in environments with extreme food scarcity; meet the Bathynomus.

Insights into how these crustaceans manage extreme food scarcity may inform biomedical research on metabolic disorders, inspire energy-efficient designs in robotics, and aid conservation strategies as oceanic food webs shift with climate change.

Deep-sea marine animal can go more than 5 years without eating, combining physical adaptations and genetic mechanisms to survive in environments with extreme food scarcity; meet the Bathynomus.

• “It is a world of perpetual night and crushing pressure, yet life finds a way,” — Jianhai Xiang, Institute of Oceanology, Chinese Academy of Sciences

Reuters

• “Deep-sea isopods have a clever 'earn more, spend less' survival strategy,” — Jianbo Yuan, Institute of Oceanology, Chinese Academy of Sciences

Reuters

• “This is surprising because bacteria and animals are very different, and such transfers are extremely rare,” — Jianbo Yuan, Institute of Oceanology, Chinese Academy of Sciences

Reuters

• “Study co-author Kahou Chu, a professor emeritus at the Chinese University of Hong Kong, said horizontal gene transfer can give organisms a faster route to new traits than ordinary inheritance alone, helping some organisms out-compete others in extreme settings.” — Kahou Chu, Chinese University of Hong Kong

Reuters

All sources agree on the stomach size, metabolic reduction and ND1 gene function. Reliability ratings differ; the Reuters article carries a moderate reliability score (45.17), while the secondary site provides no reliability assessment. No contradictory data were identified.

Deep-sea marine animal can go more than 5 years without eating, combining physical adaptations and genetic mechanisms to survive in environments with extreme food scarcity; meet the Bathynomus.