Got one without the spot on the top, Otherwise a clone of yours.
Had him over 2 years and he was the only one to survive an entire wipeout of my tank due to ICH.
I fondly remember the first day I got him.
Brought him home, aclimated him, watched him swim for a good hour and then took a nap.
When I awoke, he was nowhere in sight.
I searched inside and outside the tank for a good 4 hours and finally gave up as I now had a missing/dead fish.
Next morning dude is swiming around happy as can be
(no one told me they sleep under the sand)
I think this behavior of sleeping under the sand is what saved his life in the ICH massacre of 2001 in my tank.
It probably physically scrapes the ICH off his body.
Tough fish.