Why Do Seahorses Have Square Tails?

Why Do Seahorses Have Square Tails?    
Seahorse tails are peculiar appendages. Unlike those of most animals, the cross-section of a seahorse tail is shaped like a square prism rather than the usual cylinder. Further increasing their mystique, seahorses do not use their tails for swimming, as other fish do, but rather as giant fingers used for anchoring on coral or snatching up tasty shrimp that stray too near.

The seahorse tail is so idiosyncratic that it might be an asset for the field of robotics. American and Belgian researchers are turning to the odd extremity for clues about how to better design flexible but strong grasping devices. As they report in Science, seahorse-inspired creations could find applications in search-  and -rescue missions, industry, medicine and more. 

In order to figure out why the seahorse tail is square while so many other animal’s tails are round (rats, lizards, monkeys, cats, etc.), scientists printed out 3D replicas of the square tails and similarly sized round tails.

The researchers ran experiments on both models in which they applied various degrees of crushing and distorting pressure. They found that while the cylindrical tail gets smooshed and damaged if enough force is applied, the square tail flattens out by allowing its bony plates to slide past each other, deflecting damage away from the vertebral column and giving it the ability to absorb more energy before it is broken.

Paper:
http://www.sciencemag.org/content/349/6243/aaa6683.abstract

Full article: http://www.smithsonianmag.com/science-nature/why-seahorses-have-square-tails-180955802/#LgoBAjJk8vgRWJQ4.99

Images via Wikipedia Commons and Smithsonian Magazine.
illustrations: Michael Porter, Clemson Univ.

#biodiversity   #research   #seahorse   #3dprinting