AnAge entry for Hydra

Classification (HAGRID: 04230)

Taxonomy: Kingdom: Animalia
    Phylum: Cnidaria
        Class: Hydrozoa
            Order: Anthoathecatae
                Family: Hydridae
Genus: Hydra (Browse taxon)
Common name: Hydra
Find members of Hydra: Find members of Hydra

Observations: Whether hydra ages or not has been a topic of discussion for many decades [0002]. In a four-year study, animals did not show an increase in mortality with age. Although it is possible that these animals live much longer, considering that they reach maturity in 5 to 10 days, a lifespan of at least 4 years is impressive. The same study reported a decrease in reproductive output which could be due to the fact animals were kept in captivity. It has been argued that the extensive regeneration capacity of these relatively simple animals allows them not to age [0653]. Sexually differentiated animals, however, exhibit signs of degeneration [0735].

[1229] Schaible et al. (2015), Constant mortality and fertility over age in Hydra (PubMed)
[1150] Jones et al. (2014), Diversity of ageing across the tree of life (PubMed)
[0735] Yoshida et al. (2006), Degeneration after sexual differentiation in hydra and its relevance to the evolution of aging (PubMed)
[0653] Martinez (1998), Mortality patterns suggest lack of senescence in hydra (PubMed)
[0002] Caleb Finch (1990), Longevity, Senescence, and the Genome