Guppy Phenomenon

[This Old Spouse]

That's what my research and observation is showing. And there would be a need for females to change sex if there were no males present, otherwise the group would eventually die out.

 

[GreenA]

Hi guys. Just to add to this debate:
You can check out the "Department of Fisheries, Government of Western Australia" they state that female guppies can change sex if there is no male around. Also, just Google it and after thorough searching one can find good scientific papers on that matter....

 

[ricefish]

Please share your research quoting web pages and links.As many fish keepers that have bred live bearers for more than 20 years will dismiss your observations as late developing males
So please share or submit your findings and fish along with documentary evidence to experts for verification

 

[This Old Spouse]

My research involves googling the web, and not a laundry list of scientific papers. I honestly believe that some fishkeepers who have been raising fish for more than 20 years may have never witnessed this phenomenon, while I and many others have.

 

[Caprichoso]

It happens with Platy's and other fish, so why not guppies?

http/www.ncbi.nlm.nih.gov/pmc/articles/PMC1212134/pdf/811.pdf

 

[This Old Spouse]

 

[ricefish]

I have found no evidence in the article that shows fully functional breeders sex reversal.just seems to confirm late developing fish
and science has come a long way in over 40 years so new material would be good
If this occurs so rarely for you to have 2 cases in such a short time of keeping live bearers is amazing

 

[MBOU]

I have no doubt that it is possible for guppies to change sex, have seen it happen numerous times.

How old/big were the guppies are you watched them change TOS? Its fascinating isnt it!

I had the chance to closely watch an Adult molly changing sex. My housemate and I bought 3 female adult mollies to cycle(mature once cycled!) our marine tank, they were acclimatised over a few weeks to the salt water with no problems.

These fish were 1.5-2" so definately not youngsters and after about 4 months or so, the more dominant female got more and more aggressive, chasing the other two around and hassling them, this went on for about 2 weeks before we noticed that her fins were changing! Her dorsal fin became much taller and more showy, her colours darkened and then her triangle shaped fin flattened into a gonipodium!

No I more than believe it possible.

 

[Paradise3]

The female I had was with 2 other females, that's all. She definitely developed a gonopodium after dropping a 'litter' that I sat and watched her drop.

 

[fluttermoth]

But those females only look like males; they're not actually, fully functioning males; they can mate with females but can't fertilize them.

 

[Paradise3]

Yes but they still technically changed sex since she couldn't produce fry anymore either, she was just a sterile male.
The weird one is when you get 5 swordtails (4 females, 1 male) and the dominant female turns out to be a late developing male... or so I thought. She developed a sword but no gonopodium and she still had fry. Explain that.

 

[MBOU]

Chances are that the tail growth has to do with the hormones, being the dominant female, she no doubt had a lot of the male hormones too that leg to her growing a sword. Interesting though!

Our mollies went on to keep producing babies for a year or so..

But if a fish changes sex, infertile or not, its still a male.

 

[ricefish]

Old females sometimes take on male characteristics but the gonapodium is not functional

 

[fluttermoth]

Old females sometimes take on male characteristics but the gonapodium is not functional

+1.

Those females didn't 'technically change sex' at all, in fact that's the one thing they didn't do! They just look like males; like your old nana or aunties who grew moustaches

 

[ricefish]

I did want to compare to old ladies but resisted