Guppies changing sex

[JuiceBox52]

Okay so a few weeks ago I had 10 month old guppies, 5 females and one male... I come clean the tank and I notice one of the females is developing a lot more color. I think hmmm that's odd. A few days later she has completely lost her gravid spot and now has a gonopodium, I have been keeping guppies for a few years and never had that happen. He appears to be sterile and never chased the girls around

 

[Back in the fold]

That is weird. Fish will surprise you sometimes.

 

[Colin_T]

Swordtails do it. If a group of female swordtails are in a tank or pond without a male for 6 months, the dominant female will turn into a male and breed with the females.

Heaps of marine fish change sex too. Wrasses are all female and when they get big enough and establish a territory, they turn into males. Leather jackets (a variety of triggerfish), Anthias, Barramundi and clownfish (anemonefish) can all change sex.

Leather Jackets and Anthias start out female and turn into males.
Barramundi start out male and turn into females when they reach 18 inches long.
Clownfish start out as neither male nor female but if given a chance can turn into a male and then a female, or just straight into a female.

 

[JuiceBox52]

Swordtails do it. If a group of female swordtails are in a tank or pond without a male for 6 months, the dominant female will turn into a male and breed with the females.

Heaps of marine fish change sex too. Wrasses are all female and when they get big enough and establish a territory, they turn into males. Leather jackets (a variety of triggerfish), Anthias, Barramundi and clownfish (anemonefish) can all change sex.

Leather Jackets and Anthias start out female and turn into males.
Barramundi start out male and turn into females when they reach 18 inches long.
Clownfish start out as neither male nor female but if given a chance can turn into a male and then a female, or just straight into a female.

I did have a male with them.... who knows!?

 

[Back in the fold]

Swordtails do it. If a group of female swordtails are in a tank or pond without a male for 6 months, the dominant female will turn into a male and breed with the females.

Heaps of marine fish change sex too. Wrasses are all female and when they get big enough and establish a territory, they turn into males. Leather jackets (a variety of triggerfish), Anthias, Barramundi and clownfish (anemonefish) can all change sex.

Leather Jackets and Anthias start out female and turn into males.
Barramundi start out male and turn into females when they reach 18 inches long.
Clownfish start out as neither male nor female but if given a chance can turn into a male and then a female, or just straight into a female.

Yes, a common phenomenon in fish and very amazing. It is said among Killifish keepers that if you want a pair just put any two juveniles together. This may be overly simplistic but among the soil spawning Nothobranchius of Africa it is very true. Natures way of perpetuating species.