This is my little friend Elvis.
He is a Discordipinna Griessingeri (spike-fin goby), which have the reputation to be very shy and secretive (...if I was only an inch small, I would be hide a lot too).
He was friendly enough to sit on my Yumas and pose a little. I had to decide between staring at him in awe or grab the camera quickly.
I decided to run and when I came back he was still waiting for me
I had no time to fiddle with my settings though...oh, and of course the camera had to zoom in on the algae spots on my glass, too....