Every single time I face the amazing mimicry of the sea inhabitants, I feel the same joy as I had watching "Find the rabbit" images in my childhood (as usual, the rabbit appeared to be green and sat upside down on a tree).
Let's find on keeping a low profile Scorpaena notata on the picture!
Hint: the scorpaena has folded up it's dorsal fin and is located upside down (How do you do, Rabbit!) at the cave ceiling, with it's tail touching the upper left corner of the picture. It's eye can be easily found by bounding from the aforementioned corner diagonally downwards.