What a timely post. I just was speaking to a friend who has a pair of clowns with one of the predominantly white color morphs, and one of his lost pigmentation in the white area in the same way. We were discussing all sorts of possible things it could be (in his case there was a much larger area of depigmentation): parasites, bacteria, etc. and without the ability to scrape the fish (his or yours) I have no idea. In his case, the fish aren't acting sick--they eat well and behave normally. Is this the case with yours?

What I can do is ask a  friend who is an experienced clownfish breeder and ask if this is common, and get back to you.

Would greatly appreciate it! I have seen this once before with the 2 survivors from my first batch I raised. It appeared on them, I did a huge water change and the stripe was back to normal in a week. The only thing different this time is the water in my system is pristine. Very low nitrates. There is atleast one of these with a loss of pigmentation in each of my tanks the my system.

I can only echo what Christine just said..that looks dead on like the issues your friend is having. I have not seen it before. Water change resolved - ...maybe iodide/iodine deficiency (I know, crazy guess...and that's after at least a couple more likely culprits).

I am not entirely sure it was a water change that fixed it. I can only reason that may be it as that was the only thing I did during that time. It may have fixed itself even without the WC. Wish I had two in sep. quarentines so I could have done a test and get to the bottom of it. I know the spots are filling in on the two that are pictured with the issues. I do have some Iodine/iodide that I can add to the system. I will add some.

Iodine won't hurt (it will serve as a little antimicrobial in the water). But the odd thing here is that the area of depigmentation is showing no signs of "disease"; no rough edges, no irritated skin, no sloughing... It has sparked a bit of research into what exactly the white pigment is in fishes and why they would lose it. Now we know that fishes can change color depending on stress, mating rituals, etc, and that this is controlled by cromatophores--packets of pigment that expand or contract depending on what color the fish will display (cephalopods are even better at it). In this case, it almost looks like the "white" chromatophores (if there is such a thing, I'm throwing crazy ideas out) are either gone or stuck "closed". If a fish like this died I would love to get it to a fish pathologist to look and see if that is correct.

As of yesterday, the other fish that I know of with this was being treated prophylactically for a bunch of things, with no changes--still no pigment, but not a lot of signs of distress either. Let's keep this thread going and see if we can get to the bottom of it.

There really is such a thing as a fish pathologist ? Wow, very interesting. Mine looks to be doing much better with no signs of this issue. I will keep an eye on things to see how things go from here. Thanks for looking into this! Greatly appreciated!!!

Of course there are fish pathologists! There are fish veterinarians, though they are hard to find, at least for "pet" fish. Remember, finfish aquaculture is big business, so there is a trememdous amount of research that goes into fish (and shrimp) disease. One of the things I like about the university whare I am is they have a Marine Fish Disease Lab which does nothing but study fish disease. :)