# 1/2 male guppy



## mousey (Jan 18, 2005)

Guppy is 5 months old. Definitely not female. Gonod. Fin 1/2 changed, 2 black dots on body. All the sibs are fully colored and mature. he seems stuck in a time warp. Any ideas how to get him to switch all the way? He is in with female platies and male guppies.


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## Guest (Apr 26, 2007)

he probbably has an extra cromosome but maybe a real nice female? do males try to have sex with it? pictures?


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## TheOldSalt (Jan 28, 2005)

Extra chromsome? A missing one is more likely, this condition being the guppy equivalent of Turner's Syndrome. It happens. Hormones can treat it, but it's not worth the bother as this fish would be useless as a breeder. 
That's assuming that this is the problem of course. Since the others are all normal then it's my first guess.
I suppose it might even be a female which has turned into a halfmale from being in a tank with all males and their testosterone. Again not worth fixing.


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## Cichlidsrule (Nov 8, 2006)

Whoa, I didn't even know that was possible :O Well, ya learn something new every day.


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## mousey (Jan 18, 2005)

All interesting!:idea: 
The male guppies totally ignore it. It swims alone. ."It" does not really get accepted by any group. I may try it in the female tank and see if it will spur it into maleness. Has no sign of a gravid spot.If it spurs it to maleness i will have to be on guard that it does not mate with the females. You are probably right that it will be sterile but who wants to take that chance with 6 female fish. I am sure guppied out!;-) 
Thanks


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## Cichlidsrule (Nov 8, 2006)

So it's like a hermaphrodite fish....but if it does have gonadal dysgenesis and you move it, wouldn't it get stuck between being male or female?
It'd be interesting to see if the fry have it too (if you manage to breed it).


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## TheOldSalt (Jan 28, 2005)

No, it's not like a hermaphrodite at all. Just the opposite, it's completely sexless. It's already stuck somewhere between male and female and nothingness.
As for fry, it won't have fry. It can't have fry. Hormones only go so far, and while they can make a fish exhibit certain secondary sexual characteristics, they can't make it's meiosis function correctly, thusly it can't produce viable gametes.
Instead of an X and a Y, or two X's, this fish has a single X, called XO. Well, that second x or Y is the one which determines gender, and in this fish, it's missing, making the fish have no gender of it's own, and making it's own eggs likewise defective and unable to replicate correctly or be fertilized without causing serious scrambling.

By the way, that's quite simplified, but it gets the job done.
Even more fun, many fish aren't limited to only two sex chromosomes. Platies and Swordtails, for example, have 3, a W,X and Y. This is what makes them able to change sex so easily, but that's another thread.


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## Kyoberr (Dec 6, 2006)

Wow, that is so strange, but I agree with TheOldSalt.


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## doggydad38 (Jan 18, 2005)

There are some lines of Guppies that will change sex, female to male, but they are rare. They lose the gravid spot because the body color covers it. This happens with Mollies sometimes as well. Usually, these are sterile, but there was a thread on the Guppy Designer website discussing a line of Gups that actually produced fry generation after generation using a male that had obviously once been a female. Some marine fish can change sex as well. Some Clown fish will change sex depending on the male/female ratio so they will have the opportunity to spawn. Just something to think about.
Tony


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