CHINESE scientists have identified a biological mechanism that explains how giant deep-sea isopods can survive for extraordinarily long periods without food — in one documented case, lasting more than five years after its last meal.

The study, led by researchers from the Chinese Academy of Sciences’ Institute of Oceanology in East China’s Shandong Province, together with the Chinese University of Hong Kong and Northwestern Polytechnical University, was recently published in the journal Cell.

Deep-sea isopods grow to giant sizes despite living in nutrient-poor waters, raising the question of how they sustain such high energy demands. To find answers, the team studied two isopod species from different ocean depths, integrating comparative genomics with morphological, physiological, behavioral, and metagenomics analyses.

They discovered a two-pronged survival strategy: an enlarged stomach — taking up about two-thirds of the animal’s body — that can store large amounts of food, and an extremely low basal metabolic rate. The researchers also identified a gene named ND1, which originated from an exogenous symbiotic bacterium and was integrated into the isopod genome. This gene appears to play a critical role in enduring long-term starvation.

To test ND1’s function, the team inserted it into zebrafish, nematodes, and human cell lines. The experiments showed that ND1 increases energy use at normal temperatures but reduces energy metabolism under cold conditions. In zebrafish, it improved starvation tolerance by 37%.

“Our work not only successfully deciphers the mystery of ultra-long starvation tolerance in deep-sea isopods, but also provides an important paradigm for understanding how life balances growth and survival in extreme environments,” said Yuan Jianbo, first author of the study and a research fellow at the Institute of Oceanology.

According to Yuan, the findings may also offer fresh insights for research into longevity, obesity treatment, and aquaculture breeding.(SD-Agencies)