
Aging in Steps: Behavior Predicts Lifespan in Killifish
Researchers monitored 81 African turquoise killifish from adolescence to death, identifying 100 behavioral building blocks and showing that by early adulthood, differences in sleep and movement predict total lifespan. Shorter-lived fish nap more during the day and swim slower, while longer-lived fish stay active during daylight. Aging appears as 2–6 rapid transitions rather than a smooth decline, with coordinated changes in liver gene activity related to protein production and cellular maintenance aligning with the predictive behavioral shifts. The work suggests behavior can be a sensitive, noninvasive readout of aging and hints wearables could reveal human aging trajectories and potential intervention windows.












