Guppy inbreeding

[EmilyC]

I have a ten gallon that has become a guppy nursery. I have a few different generations of fry, the oldest group is about 3 months old. I was under the impression that it took a few months for them to reach sexual maturity, but recently read that they can be impregnated quite early. How long does it take for them to be able to become pregnant/impregnate? Should I separate them by gender? If so, at what age? Should I be worried about inbreeding?

 

[EmilyC]

Also, at what age can you determine the sex of guppies? I can't seem to tell a difference, other than that some seem to be greeting a bit of color.

 

[PockX]

Well the older they get the easier it is to tell the gender. Guppies are one of the easiest to sex. Males are the prettier ones with bigger wavy tail fins. And they can get pregant very early since there isn't much of a limit to sexual maturity compared to other fish.

 

[EmilyC]

I can definitely differentiate between male and female adult guppies but not the juvies. I guess I'm wondering if they will all be pregnant with their siblings babies by the time I can tell the sexes apart. Is that something I should be concerned about (other than the eew factor :/) ?

 

[PockX]

Eventually you will maybe get some problems. Guppies don't have a problem for the most part with that though..it usually takes to the 3rd or 4th generation to get them. To address this you can just add a couple more "new" guppies to the tank to get the genes less imbreded, if that's a word lol.

 

[PockX]

As for the gender..you can maybe see the gravid spot if you can see it. Otherwise they might be too young yet still.

 

[EmilyC]

Eventually you will maybe get some problems. Guppies don't have a problem for the most part with that though..it usually takes to the 3rd or 4th generation to get them. To address this you can just add a couple more "new" guppies to the tank to get the genes less imbreded, if that's a word lol.

Good to know- I hope to have gotten rid of most of them before I get 3rd and 4th generations.

 

[EmilyC]

As for the gender..you can maybe see the gravid spot if you can see it. Otherwise they might be too young yet still.

I'll look - if I can see a gravid spot, could they already be pregnant?

 

[PockX]

Good to know- I hope to have gotten rid of most of them before I get 3rd and 4th generations.

If you have another tank with bigger fish you can always feed the fry to them if you had too many being born.

 

[Scottyhorse]

What about checking the anal fin?

 

[EmilyC]

What about checking the anal fin?

I know the difference w the anal fun in the adults, but I'm not seeing it in the fry. I'm not really worried, I guess, about telling the difference, but I thought it would be helpful to know the difference and at what age I can tell. I was worried about inbreeding, but I guess I don't need to worry about that for a few generations. I did want to know what gender I had when I sold them or gave them away so I could give people the right balance of genders, or give them all males or all females. I guess I'll just have to wait...

 

[henningc]

The males anal fin is modified. At 3-4 wks, you can see some fry and a more pointed tip to the anal fin. They are males and need to be removed. I sort through fry 2 x wkly during the 3,4 week. If you raise the females virgins, they will grow to 2 1/2 - 3" and produce over twenty fry per drop. Once you see the black dot on the females they are hit and therefore growth will be limited. The males actually grow large whe seperated due to less mouths to feed.