July 27, 2018
As I’ve said before: ah, what you learn putting together a blog post. Click on this image to see it larger, and you will notice more detail on these squiggly lines. Guessing these could be the tracks of snails that feed on algae, that’s what I Googled. Here’s what I found: http://www.flickriver.com/groups/radula_tracks/pool/ and https://en.wikipedia.org/wiki/Radula. The Wikipedia page says that the squiggly lines are made by the snail’s radula, “an anatomical structure that is used by mollusks for feeding, sometimes compared to a tongue.” The tracks are visible in the two previous posts, too, but not as clearly.