Spider-Man Ready: 5 Animals That Regrow Parts

The Amazing Spider-Man 2 is about to swing into theaters, revealing the long-awaited fate of Lizard, the scientist-turned-monster who’s obsessed with reptilian regeneration (video). Regrowing body parts isn’t only the stuff of movies, though—many animals regenerate for various reasons. 

We asked regeneration biologist Alexa Bely of the University of Maryland, College Park, about some of nature’s most fascinating examples of rebirth. (Related: “5 Animals That Regrow Body Parts.”)

Anole Lizards

Many lizards, such as anoles, have a slick defense called autotomy, which occurs “when the animal severs a body part itself in order to distract the predator and allow the animal to get away,” Bely said.

An anole missing its tail in Puerto Rico’s Black Bull Forest Reserve. Photograph by Robert Fried, Alamy

When a lizard is threatened, it can sever its own tail using a muscular contraction. The reptiles have weak points in their tail that allow the appendage to easily break off.

That’s not the end of the tail—another one grows in its place. But a 2012 study by researchers at Arizona State and the University of Arizona found that the regenerated anole tail is not an exact replica of the original. The new tail is less flexible partly because it’s structured as a long tube of cartilage, rather than being made of interlocking vertebrae.

That’s because the physical makeup of the new appendage is “much less important than just having a tail,” Bely says—especially when losing the old one can mean saving your life.


This humble little amphibian is an astonishing regeneration multitasker, able to regrow limbs and also parts of its eyes, spine, brain, and other parts. (Related: “Newt Healing Factors Unaffected by Age, Injury.”)

Their regenerating ability has been under scientific scrutiny for centuries, and in 2013 the University of Dayton in Ohio and the Max Planck Institutes gave us new insight into how it actually happens: They made the first map of the RNA molecules expressed in regeneration, called the transcriptome. RNA is responsible for controlling the activity of cells.


These marine invertebrates have eyestalks that can’t be withdrawn into their shells. But if a predator grabs them, they have a backup plan: regrowing their eyes.

Ivan R. Schwab of the University of California, Davis, wrote in a 2007 paper in the British Journal of Opthalmology that within a few weeks new eyes regenerate to their full size.

A photo of a conch.
A toothed conch seems to eye the camera in the Raja Ampat Islands, Indonesia. Photograph by FLPA, Alamy

A number of gastropods—the group that includes snails, slugs, and conch—are underrated regenerators, Bely says: Some can even regenerate their whole head.

They’ve been largely ignored, Bely said, because researchers tend to focus on what she calls “regeneration superstars,” like newts or flatworms. (Related: “An Entire Flatworm Regenerated From a Single Cell.”)


Zebrafish, mentioned in the first Amazing Spiderman movie, are also regeneration aces, able to regrow numerous parts including fins, spinal cords, and heart muscle, a process you can see in this video animation from the Howard Hughes Medical Institute.

A 2010 study, done by researchers at the Salk Institute for Biological Studies in California and the Center of Regenerative Medicine in Barcelona, found that the two-chambered zebrafish heart can regenerate after up to 20 percent of the ventricle is amputated.

Does that mean good things for the troubled human heart?

“The challenge is finding common patterns in the regeneration process that then can be used to translate to humans, but I think there are very good reasons to be optimistic,” Bely says.

Figuring out how animals regenerate—and how to emulate it in people—will likely have to do with how an embryo develops. “The information is in the genome,” Bely says. “The trick is finding a way to start that process again.”

African Spiny Mice

In 2012, Ashely Seifert, now of the University of Kentucky in Lexington, and colleagues published a paper showing that the African spiny mouse leaves pieces of skin behind to escape predators.  (Related: “Spiny Mice Defend Themselves With Self-Flaying Skin and Fast Healing Factors.”)

That study “overturned the dogma that mammals are uniformly pathetic regenerators,” Bely says.

Even more reason to be optimistic about our regenerating future.

Follow Liz Langley on Facebook and Twitter.

Liz Langley is the award-winning author of Crazy Little Thing: Why Love and Sex Drive Us Mad and has written for many publications including Salon, Details and the Huffington Post. Follow her on Twitter @LizLangley and at www.lizlangley.com
  • Kyndal

    Weird eyes

  • My7Lives

    This is such a cool article! I know our travelers would love to see an animal like the Anole Lizard!!! If I didn’t read this article I wouldn’t of known.

  • Jasmine Syedda

    I never that about conch eyes! Thanks for the info! Creepy but cool!

  • martin

    salamadars,gecko,almost the entere lizard family also regrow limbs

  • Jordi

    These guys have nothing on planarians!

  • Laura

    I remember being out in the boat on Chesapeake Bay, we saw jelly fish and I hit them with my oar…. Then I found out that they could regenerate, that was a D’Oh moment for sure.

  • Shalane

    Sea stars also regrow arms that have been lost, and sometimes they’ll grow more then one to replace the arm that was lost. So you can find sea stars with 7+ arms 🙂

  • Liz Langley

    They are wonderfully cool – thanks for the comments, everyone!

    @Shalane Didn’t know sea stars sometimes regrow extra arms – COOL! Thanks! 🙂

  • Nelbert abella

    What about the crabs??

  • James Baker

    The spiny mouse is creepy the way that sounds is it can literally jump out uts own skin lol that would be a site

  • skye bentley

    wow so intresting i love these kind of things

  • Gabby

    This is interesting and amazing!

  • dude

    dats totes awesomeness and stuff dudes!!!

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