So I have nine frontosa's ranging from 4inch to 1/2 inch how long would it take for me to find out which one's are males and which ones are female. I know a couple of the bigger ones are starting to get there hump. But all of them look like there getting some what of the cranial hump. except for the 1/2 inch one's if you need a pic i'll be able to get you one a little later.