The melanurus wrasse is usually out and about, but I'd noticed over the past few weeks it was looking thinner and thinner. I'd watch closely when I dumped in my "dumptruck of food" as my buddy Evan used to say, and the fish would eat some food, but would also miss portions as if his aim was off.
Sometimes we may notice tiny pockets of air building up in the area where the sand touches the glass. Occasionally you'll see worms, or pods, or just an empty tiny cavern to peer at, but this time I saw something different. This is a typical view, captured with my iPhone: