Giant Deep-Sea Single-Celled Organisms! (Part 2)

In a previous post, -FUPPETS- described what could be the weirdest new creature ever discovered, the Bahamian Gromia, or "sea grape." It is fully one inch in diameter, making it the largest known single-celled organism.
Science News' website has a new story detailing these organisms and their discovery.

The above image is of a Bahamian Gromia, zoomed up. It seems these are found in relatively sterile undersea environments, and that there are lots and lots of them. The big mind-fuck is that these creatures move, and the tracks they make look very very similar to ancient fossilized tracks from the ancient Earth, tracks once though to belong solely to multi-celled organisms.

"At first, we assumed they were snails, because they had trails," said Sönke
Johnsen, an associate professor of biology at Duke University. But after sucking
up a few with the tools aboard the NOAA research submarine Johnson-Sea-Link and having a look, they figured the soft, nondescript blobs were simply some kind of elaborate poop. "We called them doo-doo balls," Johnsen said.
"We watched the video over and over," Johnsen said. The trails couldn't be the result of currents because they went in several directions at the same spot, and sometimes they even changed course. And they weren't the result of rolling downhill. In fact, one trail was found that went down into a small depression and came back up the other side.
"We argued about it forever," Johnsen said. "These things can't possibly be moving!" But they are, at a rate too slow to be captured on the sub's video. Johnsen guesses they move maybe an inch a day or less.