Guppies change sex??

[scott9]

The fellow at the LFS said guppies can change sex?? Is that true??

 

[TJT]

I think they are all born unisex, and then develop their sex as they mature. You will see females form a dark gravid spot, and males anal fins will modify.

 

[Oddball~]

They won't change sex, but certain other livebearers can temporarily.

 

[Harlock]

They won't change sex, but certain other livebearers can temporarily.

Guppies do not change sex, nor do certain livebearers that I know of. There was some old theories about swordtails changing sex, but really, all fry are born "looking" female but with the internal organs onf one gender or another. Any fish that "changed sex" was simply a late bloomer. Having said that, this applies to freshwater fish. I know that there are in fact several reef-dwelling SW fish that can change sex for a spawn.