Hi!

I am doing a behavioral experiment with zebrafish where I only need to mark a focal individual for 20 minutes. I need Ethovision to detect the particular fish, and in my experience, it is not very accurate without a mark. I have been looking in the literature, but I have only found marks that last a couple of days. I can´t dye the focal fish because I am testing social behavior, and I don´t want to use an invasive method because of the question we are testing. I was thinking of painting a little spot with non-toxic nail polish in the back of the fish, but I am concerned about the chemical implications because I haven't found someone that has done it before. Thank you!