521447418

521447418

Green Madagascar Day Gecko (Phelsuma madagascariensis) in the Masoala rainforest hall of Zoo Zurich (Switzerland) on June 15, 2012. Built in 2003 as a small replica of the Madagascar Masoala rainforest, the hall covers an area of more than 10'000 spare meters and is one of Zurich Zoo's main attractions.

Photo by: EThamPhoto

EThamPhoto

How a Lizard Loses Its Tail (and More Importantly, Keeps it Attached)

Thanks to a complex internal structure, lizards can shed a tail in a pinch… yet keep their tails attached when they need them.

March 29, 2022

Losing a tail isn’t great, but being eaten by a predator is far worse. In the animal kingdom, the autonomy of a limb, or self-amputation, is a common defense strategy. While this is a useful biological feature in many situations– how do animals prevent their detachable limbs from popping off at any minor inconvenience?

The answer lies in a hierarchical internal structure.

1219133047

1219133047

Lizard with blue tail in Batam, Indonesia.

Photo by: Ais Setiawan / EyeEm

Ais Setiawan / EyeEm

Lizard with blue tail in Batam, Indonesia.

“It has to find the just-right amount of attachment, so it doesn’t come off easily. But it should also come off whenever it’s needed,” says Yong-Ak Song, a bioengineer at New York University. “It’s a fine balance.”

A lizard’s tail has to hang on tight enough that it doesn’t fall off from minor bumps and scrapes but can drop off in case of emergency. The internal design of a lizard tail features micropillars, prongs, and nanopores that act as a series of segments that clip into each other in rows– like plugs fitting into sockets.

The tail can break off along any of these rows, called fracture planes. This allows the lizard to decide how much of its tail it needs to sacrifice in a given situation.

522191698

522191698

Autotomy or self-amputation in a lizard.

Photo by: Paul Starosta

Paul Starosta

Autotomy or self-amputation in a lizard.

To understand this internal structure, scientists studied lizard tails from three different species. By giving the tails a gentle tug, the team separated the limbs from the lizard bodies. Then, they studied the severed appendages under a scanning electron microscope, finding that lizards’ nanopores help with the adhesion of their tails by 1500%.

The researchers described lizards’ prong-pillar-pore structure as following the Goldilocks principle– not too tight that the lizard can’t self-amputate, but not too lose that the tail falls off on its own.

This adaption is vital to lizards’ survival. Losing a tail is a costly mechanism for a lizard– slowing its ability to run, jump, and mate… and jeopardizing its ability to avoid becoming a future predator’s lunch.

Next Up

Scientists Have Decoded the Universal Language of Honey Bees

Scientists just made a real-life breakthrough in understanding how bees talk to each other. Learn more about decoding the honey bee waggle dance.

Meet Dogor, Your 18,000-Year-Old Best "Friend"

Dogor may have died 18,000 years ago, but his body has remained perfectly preserved — all-the-way down to the whiskers.

Storm Dennis, When 2 Become 1 Menacing Bomb Cyclone

What is a bomb cyclone? And what’s up with Storm Dennis being such a menace in the UK?

Frozen Ice Sculptures Could Save a Himalayan Cold Desert

Ladakh, a Himalayan cold desert with stunning mountains and blue waters is no stranger to the impact of a changing climate. But could manmade glaciers save this landscape and its people?

Volcanology: The Study of Volcanic Activity and Predicting Eruptions

The study of volcanoes and collecting data such as seismic activity, temperature, and chemical changes can help predict eruptions and save lives in the process.

Narwhal: The One With Two Waggly Tails?

Meet Narwhal, an adorable pup with two tails. But how did this anomaly happen? Read on to learn more.

The Ocean Cleanup Successfully Catches Plastic in Great Pacific Garbage Patch

Humankind’s disgraceful rubbish footprint swirling between California and Hawaii may have just met its match.

Clean Air Tech and Pollution Reduction Post-COVID

One of the unintended positive consequences of the coronavirus pandemic is a reduction in air pollution.

Ancient DNA Reveals New Evidence, Changing What We Know About Human Evolution

New DNA evidence found in sediment from Denisova Cave in Siberia reveal that it may have been a common meeting place that overlapped with Neanderthal, Denisova, and Homo sapiens. Could this have altered our evolution as modern humans?

Launching Rockets Into the Aurora Borealis - and Other Stories About the Northern Lights

Those that live in the Arctic Circle echo that no words can do justice to the sheer experience of the ‘celestial dance’ that occurs in the skies.