Starfish Can Regrow Missing Limbs fact

Starfish Regeneration

Some species of starfish can regrow missing limbs, and a few species can actually regrow a whole new “disk” (the center party of their body) from a limb!^[1][2]

In other words, not every species of starfish can regrow every part of their body, and some can only regrow parts under the right conditions (most need the disk attached, some need a part of the disk, a few don’t need the disk at all), but generally the rumors about star fish are true.

FACT: Yes, that means starfish that can regrow a disk from a limb can shed its own limbs to reproduce more starfish. So while starfish can mate to produce offspring, they can also reproduce as larva or adults using their powers of regeneration. Consider this excerpt from Wikipedia, “The larvae of several species of starfish can reproduce asexually before they reach maturity. They do this by autotomising some parts of their bodies or by budding. When such a larva senses that food is plentiful, it takes the path of asexual reproduction rather than normal development. Though this costs it time and energy and delays maturity, it allows a single larva to give rise to multiple adults when the conditions are appropriate.”

FACT: Starfish don’t lose their limbs because they are accident prone, they actually shed their limbs. What happens is that starfish soften the connective tissue attaching their limbs in response to specific nervous signals. So if a starfish is under attack and needs to lose a limb to escape, they will shed a limb as a natural response.

FACT: A starfish’s mouth is on its disk. If a starfish that can regrow its disk loses its disk, the remaining limb will live off the nutrients stored in the limb until it can regrow a mouth.

1. Starfish. Wikipedia.org.
2. Purification and Partial Characterization of an Autotomy-Promoting Factor from the Sea Star Pycnopodia helianthoides. hJournals.uchicago.edu