Strange tang behavior

[Ruth]

Mine does the same thing and every so often just to keep me on my feet he will also make a big splash with his tail while he is up these gulping air. If I happen to be sitting at the computor beside the tank it is not unusual for me to get splashed (and startled).
Mine sleeps totally upsidedown between a rock and my overflow. All you can see is his yellow tail sticking up in the air.