yellow tang, white line

[365seasons]

we bought a small yellow tang over a month ago. It has been thriving and doing really well, getting plumper and everything. Its always been very vibrant in color and active.

We found a hitchhiker crab in the tank last night, and earlier today were trying to catch it, so little bit of stir up in the tank, but no more than a cleaning...


Came home tonight to find a solid white stripe down the center of our now very pale yellow tang.. Is this lateral line erosion, or just stress?

Anything we can do to help?

We just put in some nori and spirulina pellets and turned all the lights out.

Thanks in advance.