Deep-Sea Pill Bug Survives Five Years Without Food

There's an isopod (aka a pill bug) the size of a football living nearly 1,000 meters (3,280 feet) underwater, and it hasn't eaten since the last time something dead sank past it. That was, potentially, years ago. It's fine.

The supergiant bathynomid, a deep-sea isopod and distant relative of the roly-polies in your garden, can go more than five years without food. Researchers from the Institute of Oceanology of the Chinese Academy of Sciences just published the first real explanation of how it pulls this off, and the answer turns out to be stranger than the question.

The isopod runs a two-part system. First, the structural setup: its stomach occupies roughly two-thirds of its entire body. When food arrives, like a sinking fish carcass, the animal gorges. What fills that chamber isn't just food; it's a microbial community tilted heavily toward Chlamydiae, bacteria associated with lipid storage rather than digestion. The animal isn't just eating. It's stockpiling.

Second, the metabolic trick. Buried in the isopod's genome is a gene called ND1, acquired not through inheritance but through horizontal gene transfer from a symbiotic bacterium, a piece of microbial machinery the animal essentially absorbed and repurposed. Under cold, food-scarce conditions, ND1 suppresses mitochondrial activity, dialing the animal's energy burn down to nearly nothing. When researchers introduced this gene into zebrafish, starvation tolerance improved by 37 percent. One gene. Cold water. Thirty-seven percent.

This is gigantism running on almost no fuel, sustained by stolen bacterial code and a stomach that takes up most of the body.

Five years of no food. No pill bug complaints on record.

Read the full story at EurekAlert!, June 2, 2026

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