Image by Christopher Mah, from NOAA’s Okeanos research vessel in the Nitinat Canyon, Pacific Ocean
Zoom in on the photo and realize that all those tiny holes and dents on the right side of the starfish are actually starfish footprints! Or podia prints, to be biologically precise.
While NOAA’s ocean exploration vessel Okeanos was recently plying the Pacific Ocean waters off the coast of Washington State, Christopher Mah, a world-renowned starfish expert, was working with the Okeanos research team, identifying ocean life that came into the view of the research ROV.
As the ROV slowly moved through the Nitinat Canyon on Dive 8, Mah suddenly got excited.
“We get to see STARFISH TRACKS!” he live-tweeted after exclaiming in delight on the livestream, ” … little tube feet tracks in the sediment! [We’ve] never seen those before!”
Starfish aren’t fish and are often called sea stars. They have five or more arms, and each arm has hundreds, sometimes thousands, of tiny feet called podia.
The way starfish use their thousands of podia to move or “walk” is fascinating and is explained in-depth and with some cool, clear videos here.
This starfish has extended its hundreds of podia, or tubular feet, to move.
Screenshot of video via KQED
“If the sea star needed to know what everything each one of its tube foot is doing, it’s a lot of information to keep track of,” notes mechanical motion engineer Eva Kanso. And since starfish don’t have brains, there’s no way for them to keep track of what each podia is doing. “So it seems that every single one of those tube feet has some autonomy,” Kanso says.
“I think tube feet are amazing,” said Kanso, who studies the physics of animal motion. “Every single one of them is both a sensor and an actuator that does the work.”
We live on a remarkable ocean planet 🌊
Starfish tracks, wider shot. Image by Christopher Mah in the Pacific Ocean’s Nitinat Canyon during NOAA Ocean Exploration’s 2023 Shakedown + EXPRESS West Coast Exploration
Oceanwire 