Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA.
Exp Gerontol. 2019 Jul 15;122:92-98. doi: 10.1016/j.exger.2019.04.018. Epub 2019 May 4.
Negative senescence, a decrease in size-specific mortality of large individuals, is shown by sea urchins. Sea urchins have indeterminate growth and size-specific gamete production increases throughout life. These characteristics are present in short-lived species, Lytechinus pictus and L. variegatus as well as ones that are long-lived: Mesocentrotus franciscanus, Strongylocentrotus purpuratus, Echinometra mathaei, and Stomopneustes variolaris. Both short and long-lived species have cellular mechanisms that counter senescence. Many groups of organisms have species that are short-lived as well species with individuals that may attain ages of many hundreds of years. Generally it is assumed that short-lived species show senescence but results for sea urchins indicate that lack senescence may be present even when mortality is high.
消极衰老，即大型个体的特定死亡率降低，在海胆中表现出来。海胆具有不定向生长的特点，其配子产量会随着个体的生长而不断增加。这些特征存在于短寿命物种中，如 Lytechinus pictus 和 L. variegatus，以及长寿命物种中：Mesocentrotus franciscanus、Strongylocentrotus purpuratus、Echinometra mathaei 和 Stomopneustes variolaris。短寿命和长寿命物种都有对抗衰老的细胞机制。许多生物群体都有短寿命的物种，也有个体可以达到数百年的寿命。一般来说，人们认为短寿命物种会出现衰老现象，但海胆的研究结果表明，即使死亡率很高，也可能不存在衰老现象。
