[BonsaiNut]

Here is a very easy experiment to demonstrate that environment impacts bar development in juvenile clown fish.

Take a group of juveniles (just post larval stage) and split group in half, taking photos of the two populations. Place the two groups in two different environments - i.e. keep one group in a commercial breeding grow out tank, and take the other group and place it in a floating grow-out cage in someone's reef tank. Use the same food and feeding frequency if you can. Compare the two groups after a couple of months have gone by.

I have done this and come out with VERY different results where the two groups looked like they came from completely different parents. I don't have photos, but the group in the reef tank colored up much more quickly, had much more extensive black coloration, and had completed bar development much more quickly than the other group. (And some individuals in the first group never completely developed three bars).

Why? I don't know. It was too difficult to control the two environments so that you could only tweak one variable. One of the tests I had wanted to do at some point was create a dual grow-out tank setup so that you could run the same water, food, etc, and test different lighting, different foods, etc, individually to determine best results.

Just thought I'd add this to the discussion.