That Bad Boy Can SWIM?

NOAA 
Squaring off against evolutionary conjecture is a strange critter called the boxfish. These toxic avengers look like they have the maneuverability of — well, a box. But that is the opposite of the truth.


Kind of cute, really.

But they have some surprises. In fact, they are so well designed that they are self-correcting, and even change the water flow. Auto manufactures have copied their design. They are being checked out as inspiration for undersea robots, too.
With their ‘boxy’ shape and rigid bony carapace that covers most of their body, boxfish look somewhat awkward compared to most other fish. As Science journal commented recently, ‘One look at the aptly named boxfish, and you might expect it to swim as well as a barn would fly.’ 

In reality, boxfish are able to swim extremely smoothly. This is even more remarkable considering where they live—reefs washed by highly turbulent and unpredictable waters. But even when continually buffeted by swirling currents, boxfish make only the slightest of deviations from their straight swimming paths, as they correct for unseen eddies and turbulence.
You really should read the rest of this short article, "How Does a Box Swim?"