Species of the genus Hydra show no senescence and have the potential for extremely long life spans. Previous studies have demonstrated both constant mortality under constant laboratory conditions and instances of high mortality under specific environmental conditions. Here we review these studies and argue that these unique life history traits can be understood as adaptations to a specific ecological niche, given Hydra's specific anatomy and biology. We argue that these adaptations are facilitated by the genet-ramet organisational system of a clonal organism.