Wow! How did you manage to count them? :-DHello again, I am still learning. How long before I can tell the sex of my babies? I have approx. 30 new guppy fry... 3 are 1 month old, 11 were born day before yesterday and 16 today. I am having trouble telling on the month old ones.
This method can be modified a bit to fit what you have available but the general process willl be the same. As you get more experienced it will become easier to start differentiating the sexes earlier and earlier to allow you to segregate the genders and allow for maximum growth and development before breeding begins and so that you can selectively breed if that is your wish. Another option is to use a small glass container (ie babyfood jar) in which you can place a single fry at a time, examime carefully for gravid spot or possible gonopodium development and sort accordingly placing the "sures" in separate containers and the "not sures" back into the main fry tank for a re-check a few days laterFirst, you will need a two-gallon aquarium and a piece of black cardboard that can cover the back of the aquarium. Cut a hole about 1/2 inch in the center of the cardboard and place it on the back of the aquarium. Place a small lamp with a frosted 100-watt bulb directly behind the hole. Using the water from the aquarium containing the new fry, fill the two-gallon tank. Carefully remove two or three fry from the tank and put them in the sexing tank. Wait until early evening when the sun is dim, and using a magnifying glass, observe the guppy as it swims through the beam of light. Under these specialized conditions, the gravid spot of the females can be detected. Males will not have this spot. Segregate the males and