Martínez D E
Department of Biology, Pomona College, Claremont, California 91711-6339, USA.
Exp Gerontol. 1998 May;33(3):217-25. doi: 10.1016/s0531-5565(97)00113-7.
Senescence, a deteriorative process that increases the probability of death of an organism with increasing chronological age, has been found in all metazoans where careful studies have been carried out. There has been much controversy, however, about the potential immortality of hydra, a solitary freshwater member of the phylum Cnidaria, one of the earliest diverging metazoan groups. Researchers have suggested that hydra is capable of escaping aging by constantly renewing the tissues of its body. But no data have been published to support this assertion. To test for the presence or absence of aging in hydra, mortality and reproductive rates for three hydra cohorts have been analyzed for a period of four years. The results provide no evidence for aging in hydra: mortality rates have remained extremely low and there are no apparent signs of decline in reproductive rates. Hydra may have indeed escaped senescence and may be potentially immortal.
衰老，是一个随着实际年龄增长而增加生物体死亡概率的恶化过程，在所有经过仔细研究的后生动物中都有发现。然而，对于水螅（刺胞动物门的一种独居淡水生物，是最早分化的后生动物群体之一）的潜在永生能力，存在诸多争议。研究人员认为水螅能够通过不断更新其身体组织来避免衰老。但尚未有数据发表来支持这一论断。为了测试水螅是否存在衰老现象，对三个水螅群体的死亡率和繁殖率进行了为期四年的分析。结果没有提供水螅衰老的证据：死亡率一直极低，并且没有明显的繁殖率下降迹象。水螅可能确实逃脱了衰老，并且可能具有潜在的永生能力。
