Dragonette (2 inches long)
Dragonette sifting sand. Unlike most of the other creatures in this section, dragonettes such up mouthfuls of sand and "sift" it through their gills, gleaning from it any algae or small plankton living on/in the granules.
I'm not sure what this tiny (less than 1 inch long) fellow is, but he appears to be some type of young goby, and the fact that he is showing a large dorsal fin (as a warning to the big creature taking his photo) suggests that he, too has some venom in that spine...