How do you recount the sex of my damsel fish?
Answers: Most damsels are isomorphic (no distinguishing differences), some have a difference in color or one a lacking of color. what helpful is it? If you want to do it the hard way you can remove the fish and take a magnify glass look at the area behind the anal fin and within will be two holes, males holes are two different sizes where females are the same size. I know that is method too much for a three dollar fish, but you asked.
Its hard to tell, females are generally bigger.