Many starfish species can regenerate lost arms, and in some cases a single detached arm can regrow an entire body, a capability that aids survival and showcases remarkable regenerative biology
Regenerative capacity across species
Starfish, or sea stars, display impressive regenerative abilities that vary by species. Most can regrow one or more arms if they are damaged or lost to predation, while a few tropical species are able to regenerate a whole new individual from a single severed arm provided part of the central disc is included or, in rare cases, from the arm alone given favourable conditions.
How regeneration works
Regeneration proceeds through coordinated wound healing, cell proliferation and patterning. Cells at the injury site dedifferentiate or recruit proliferative cell populations that rebuild tissues including muscle, skeleton, nerve and epidermis. Radial nerve and coelomic tissues help guide regrowth so that a functional arm with tube feet and sensory structures is restored over weeks to months depending on temperature and species.
Ecological benefits and behaviours
Autotomy, the deliberate shedding of an arm, is used defensively to escape predators, and subsequent regeneration allows the animal to recover lost function over time. This strategy reduces immediate mortality risk and contributes to longevity and resilience in dynamic benthic ecosystems.
Research and broader relevance
Scientists study starfish regeneration to understand fundamental mechanisms of tissue renewal, neurobiology and immune roles in repair, with implications for regenerative medicine and comparative biology. Ongoing research explores cellular sources, signalling pathways and the role of the nervous system in orchestrating accurate pattern formation during regrowth.
Takeaway
Starfish regeneration exemplifies nature’s capacity for rebuilding complex body parts, balancing defensive strategies with long‑term recovery and offering valuable insights into the biology of regeneration across animals.