One funny thing I've noticed this morning while feeding Desmoda is that the surface of the water has bubbles scattered all over it that aren't moving at all as though they are stuck. I'd understand that they wouldn't move if they were attached to a solid surface such as a wall, but in the middle of the tank? My filter has had a lower amount of flow to it due to some alterations, but particles still move around on the surface due to the water flow. Not the bubbles, though, or even the food as I dropped it on to the surface.
Then, as I watched Desmoda eat, stringy, mucous-like strands either came from him or were in his vicinity. That was when I postulated that, combined with the static bubbles and even static food that I dropped on the surface (usually it goes off with the current), that he may have made so many spit bubbles that the mucus has kind of made a film over the surface of the water. I took some of the surface water out with my turkey baster and there is some more movement apparent on the surface now, so I'm guessing that it is mucus. What supported my idea was that I watched him expel some bubbles out of his gills and they popped instantly as they hit the surface. I also saw him release bubbles from his mouth after taking a gulp of air and they did not pop. It seems like he is comfortable enough to begin making bubble nests or the bare minimum of such. XD There is a small mound of them in the corner of the tank closest to me when I sit at my computer, and they look like they have a film covering them, but more like water has pushed itself over the tops of them, creating a seal-like appearance.
Very exciting! :D