Guppy Breeding Colony Start Size

[Benny]

Hey all. What's the ideal amount of male / females to start a colony of guppies? Obviously you don't want to do a trio because inbreeding would be guaranteed, but what is the ideal amount to start with to keep inbreeding to a minimum?

[Henry the fish keeper]

Idk maybe one female and one male obviously that is not the best choice because males with constantly chase females.

[lefty o]

if you dont want inbreeding (its going to happen no matter what), i would suggest 2 males, and 5 to 6 females.

[PineSong]

I’m wondering why the concern about inbreeding though? Either way, I think the best way to avoid that would be to remove males after a few days once they have had a chance to mate with whatever females there are, then remove juvenile male fry before they can breed and replace them with males from another source. Or, remove the female fry and replace them with outside females. Not sure if either of those could be called colony breeding though. I started out with a reverse trio of ginga sulphureus guppies in late summer and probably have sixty now. So you can build a colony quickly even with just one female.

[Minanora]

Another thing to consider is that females will likely come pregnant if you're getting them from a breeder. So there will be genetic diversity there even if you only buy a pair.

By breeder I mean any shop that sells single strain lines of guppies

The female will be carrying fry from many other males that she was with before being bagged with the male you get.

Edited March 17, 2022 by Minanora

[sumplkrum]

You'll always get inbreeding because you're starting with a limited number of fish. The only way to diversify is to cross them out with other populations every few generations.

With guppies inbreeding is usually the goal because you are trying to maintain the strain (look of the fish). To avoid the negative effects of inbreeding, you out-cross to other populations. Dedicated breeders will have multiple lines or communities of similar fish so they can maintain a reasonable diversity and chose traits to maintain or improve the line.

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2 males and 6 females is a reasonable start. You have enough genetics in 8 fish to be ok for a good while. Maintaining the strain will come down to culling poor fish and choosing good second/third generation breeders.

If you were to have 1 male and 3 females, that wouldn't be a bad start either as long as the male has all the traits you want to reproduce. The risk though is that something happens to the one male, then your breeding program is stalled out.