What a nice picture. I love the contrast of the white fish along with all the orange ones. Not much you could even do to improve such a nice photo - perhaps just a bit cleared focus which is hard to do in the water.
There was quite a lot of potential for this image, I think the composition could have been tweaked a little, I think the white fish would have been better more off centre. 4/10
I can't help but to think how nice this would be if all of the other fish were white and the one in the middle was orange. Nice image anyway, I would have made it larger, good luck!
Really beautiful shot. Love the lone pink/white fish. One suggestion for future challenges (although it won't affect my vote) - it seems images that are a bit larger in pixel size seem to do much better in these challenges. If you found it hard to get to 150 kb, you may want to try resampling down to 67 dpi or something and still go with the larger file size. I find even when you save things at .jpg quality 7 and 8 you can still get a good photo. Good luck with this one. It's one of the best so far.