Sea Cucumber Fragments Live for Years-A New Kind of Immortality

A severed piece of the Atlantic sea cucumber Psolus fabricii has survived in a seawater tank for more than three years, a record for any detached animal tissue.

Longevity Beyond the Whole

Researchers from Memorial University of Newfoundland, led by doctoral student Sara Jobson, observed the fragments in natural seawater tanks, noting continuous growth and wound repair despite lacking a gut or mouth. The tissue retains a robust immune system and chemical defenses, preventing microbial infection, while its cells keep dividing to form new tissue.

Mechanisms Behind the Zombie Tissues

Fuel comes from absorbing dissolved amino acids or cannibalizing its own muscle, a strategy that keeps the fragment alive without external nutrition. Other sea cucumber species tested in the same study perished before three and a half months, underscoring the exceptional longevity of P. fabricii fragments. Scientists have yet to measure telomere length after repeated cell divisions, so true immortality remains unproven; however, the sustained coordination of biological processes over years is unprecedented.

Implications for Biology

The evolutionary puzzle remains: why would a nonreproductive scrap of an organism remain viable for so long? It may simply be a by-product of P. fabricii's regenerative prowess. If these fragments are indeed self‑sufficient, they could be drifting through oceans worldwide, effectively acting as "zombie" tissues. Future work will need to track telomeres and metabolic rates to confirm whether these tissues truly defy senescence, but the findings already reshape our understanding of tissue viability. In the meantime, the discovery invites a reevaluation of what constitutes death in regenerative species and hints at new avenues for studying cellular longevity.

Source: The secret to immortality might be a sea cucumber
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