<P> Other species have been observed to regress to a larval state and regrow into adults multiple times . </P> <Ul> <Li> The hydrozoan species Turritopsis dohrnii (formerly Turritopsis nutricula) is capable of cycling from a mature adult stage to an immature polyp stage and back again . This means no natural limit to its lifespan is known . However, no single specimen has been observed for any extended period, and estimating the age of a specimen is impossible . </Li> <Li> At least one hydrozoan (Laodicea undulata) and one scyphozoan (Aurelia sp. 1) can also revert from medusa stage into polyp stage . </Li> <Li> The larvae of skin beetles undergo a degree of "reversed development" when starved, and later grow back to the previously attained level of maturity . The cycle can be repeated many times . </Li> </Ul> <Li> The hydrozoan species Turritopsis dohrnii (formerly Turritopsis nutricula) is capable of cycling from a mature adult stage to an immature polyp stage and back again . This means no natural limit to its lifespan is known . However, no single specimen has been observed for any extended period, and estimating the age of a specimen is impossible . </Li> <Li> At least one hydrozoan (Laodicea undulata) and one scyphozoan (Aurelia sp. 1) can also revert from medusa stage into polyp stage . </Li>

What is the longest living species on earth