The African turquoise killifish has one of the shortest lifespans of all vertebrates: it reaches the ripe old age of only three to twelve months. That short life expectancy – as well as the huge variation among individuals – makes it perfect for studying longevity. Experiments that would take three years in a mouse take just six months in the killifish, says Alessandro Cellerino at the Scuola Normale Superiore in Pisa, Italy.