It is called stereotypic behaviour...or stereotypy. It is really common in predatory cats and polor bears kept in captivity. Unfortunately, we see it a lot in our fish as well. I know more than I would like to about it due the experience I've had with my Blue Throat Triggers.

Everytime I watch my remaining female Blue Throat, it makes me kind of sad...which isn't how I like to feel when I look at the aquarium.

Based on what I've read, the best solution seems to be to alter the environment in ways that keep the animal interested and provide something for it to do or explore. I'm sure that is difficult to do in a reef aquarium.

Interesting weblink... (well..interesting to me, anyway)
http://www.aps.uoguelph.ca/~gmason/S...ur/index.shtml

lol i agree with kein. fish are hilarious, my tank likes to get blasted by the power head and does a 360.

Weird. I saw a Trigger doing this on youtube this morning >< At any rate, Thanks for the article. I try to adjust the flow in my tank every month or so and change some Aquascape (As much as the present scape will allow.

That is hilarious... It needs some Ridalin

I was considering given him brine shrimp for a few days.
To give him some energy and see how fast he can actually do it.
Since it seems unlikly that this is heathy behavour ive moved the fragrack.
Hes still up and down in the corner but he does swim away often enough to do other things now.;

Defineatly not normal behaviour for regal tangs.

What is the length of your tank and the size of the tang?

Naesco not to start anything but I recall when you sold your 130 gallon (this tank is a 180) you listed a bunch of tangs in a tank far too small for them in my opinion.

regal tang 5in
sohal tang 7 in
purple tang 7in

This 6-foot rule doesn't count for much I think when your tank is 18" wide.

6x2x2
180g
and 5 inches body not including tail and lips

Frag,
Well your tank is large enough to accommodate the tangs.
It must be just the fish.