Sexing Guppy Fry

You won't be able to sex them until they are at the very least a month old, probably longer. From then, the males will start to get colors before the females. The male's anal fin will start to appear as if he's folded it half way, but actually this is his gonopodium starting to develope. Hope this helps.
 
"At 4 to 5 weeks, fry should be separated by sex. Remove or isolate only enough females that you will need to set up your next set of breeders. Females are easily distinguished from males as they will exhibit a dark area just above the anal fins where fertilization takes place. This area is also referred to as the "gravid spot". Cull out (discard) any inferior fish. If you were able to acquire a top quality strain, there should be little culling required. If you find yourself culling more than 20% of a litter you are probably working with a strain that is not pure. "

This is from www.showguppies.com.


jim
 
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The egg spot is there pretty much from the beginning I think. Its just too small for you to see. After like a week or two its easy to tell by that.
 
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