Here is a bit more background on the purpose of these patterns:

Even as articles bounced around the web it was still difficult to imagine how a tiny fish could create such a large design in the sand, even when staring directly at photographic evidence. Finally, video has emerged that shows just how the little guy delicately traverses the sand in a rotating criss-cross pattern to create a sort of subaquatic spirograph. The textured sand sculpture not only attracts mates but also serves as protection when the fish pair and lays eggs.

This is supercool and apparently videos of this up until this point have been fairly rare.

We hope you enjoy watching!