Subject: A Yellowmouth Moray (Gymnothorax Nudivomer) is quite annoyed with the presence of a few too many Clear Cleaner Shrimps (Urocaridella antonbruunii). These translucent cleaners often appear in large numbers which can be, like in this case, an unwelcome gift for the host.
Technique: It is almost never good to film a subject from above. However, there are two exceptions; when your subject is only visible from above or when it is impossible to place the camera lower due to a physical obstruction. Try always to place your camera as low as possible and film upward.