Tang behavior changes?

[treylane]

I realized the other day that the 2.5" scopas tang that I added to the tank a couple years ago isn't a baby anymore. He's ~4" long in a tank a bit under 4' long. He's big enough that I worry he'll be cramped for space at some point soon, but what seems strangest to me is that he used to be a hyperactive little @#%* to the other fish, and now he's MUCH more docile. He's not an especially active swimmer, doesn't harass the other fish, and is generally a model citizen. Do these guys get calmer as they get older, or is this a sign of crowding or what?

 

[jhentr]

IME with a mimic tang, he was an active swimmer when small. Once he hit his adult coloration and got bigger in my small 42" tank, his swimming stop and he developed HLLE. I traded him back at the LFS where I got him.

His diet didn't change and he was the only tang and dominant fish in the DT.

 

[reeferstace]

I think you are seeing the effect of crowding.

 

[treylane]

He hasn't had any health problems, he's got quite a bit of weight on him, no lesions or any other signs of disease. He'll occasionally spook and bolt for the rocks over some minor issue (like if I bump the turkey baster on the bracing) but up till now I've attributed that to tangs not being the smartest fish in the ocean...