Hydra is one of the few known immortal animals, but the cellular and molecular mechanisms underlying this phenomenon remain largely unclear. Telomere lengthening is recognized as one of the factors contributing to enhanced proliferative potential at the cellular level. Telomerase activity is known to support both cellular and organismal longevity. In this study, we characterized the telomerase of . The expression pattern of the telomerase catalytic subunit () mRNA correlates with regions exhibiting high proliferative potential and remains unchanged during budding or regeneration. These findings were further corroborated by measurements of telomerase activity. Our data suggest that telomerase may play a role in the immortality of .