Xiphophorus Guentheri

[mac111]

i just got some Xiphophorus Guentheri and they are young fish just over an inch long
so i know they are to young to sex yet, but i was told when the first male appears to move him
out of the tank, that way i'll get more males, cause another fish will turn into a male [ confused here ]
i thought the sex of a fish would be set at birth, i mean i've never had a female guppy or endler turn into a male,
so i'm beginning to think that they were just pulling my leg, having a laugh at me, grrrr
what they said seems totally unbelievable that, if you have a tank full of female swordtails one will turn into a male
can anyone tell me if this is true or not

thanks inadvance

dave

 

[mcqc4]

No they don't change sexes. Born a male, stays a male and vice versa.

 

[TwoTankAmin]

Actually, Xiphophorus females can change sex to male in the absence of males. The reverse, male to female, does not occur. Google "Xiphophorus + sex change"

 

[the_lock_man]

Actually, Xiphophorus females can change sex to male in the absence of males. The reverse, male to female, does not occur. Google "Xiphophorus + sex change"

Genuinely, rather than producing eggs, they start to produce sperm? Remarkable.

 

[mac111]

Actually, Xiphophorus females can change sex to male in the absence of males. The reverse, male to female, does not occur. Google "Xiphophorus + sex change"

Genuinely, rather than producing eggs, they start to produce sperm? Remarkable.

even more confused now after reading 2 full pages of posts from the google search,[about 25 pages] and some say yes it can happen, when a female gets old and loses some hormones,
others say no it does not happen, that the first males show that they are males early, and growth slows down, the ones that show that they are males latter grow much bigger
and it's better to have the large males, for the genes, one post said the small males were sneaky and fast ... haha.

but i am still confused but at least now i know they werent just winding me up .. phewww

THANK YOU TO mcqc4... twotankamin... and the_lock_man for replying


this is a post i found that seemed to make sense to me,

It's a myth that they change sex. What actually happens is some males dont develop fully so that they remain 'hidden' to the dominant male, looking like females, then if the opportunity arises they complete their development by growing gonopodiums and swords, becoming fully functional adult males.

 

[fish48]

above post is correct It's a myth that they change sex.

 

[helterskelter]

Sex changing in Xiphophorus is a myth. Genetical they stay male/female.
However as already stated, in old females, the male hormones are produced which makes then develop a sword and a gonopodium, however their still female and they do not produce sperm.

Many male Xiphophorus when their growing up, are suppressed by the other males, this is why removing males will allow then other to mature. However if you leave then all together, i've see some males take over 12 months to mature!

 

[TwoTankAmin]

After doing a lot of searching I have concluded that there is no proof that Xiphophorus change sex. I can only find suggestions that some may and that some do not. So I am now up in the air on this issue. I will keep looking but for now have revised my thinking to say the jury is still out. I can not say with any certainty that there is a definitive yes or no answer.

However, this is an interesting read on this topic SEXUAL DIFFERENTIATION IN THE TELEOST FISH XIPHOPHORUS HELLERII, AS MODIFIED BY EXPERIMENTAL TREATMENT
It does allow for the possibility of sex changing. See the Discussion section.

 

[OldMan47]

TTA where do you find scientific evidence of a sex change in Xiphophorus? It is never seen, as far as I know, because it is determined by x and y chromosomes in much the same way as in most mammals. We do see male sex characteristics not being shown in some males of X. helleri when they are raised with other dominant males of their own species but that does not mean that they are females. It simply means that they are afraid to show that they are males. The rest of the Xiphophorus genus are not known to hide their gender as well as helleri so I suspect that is what you are experiencing.
From what I have been able to dig out from places like fishbase.org, it seems that Xiphophorus guentheri is really just a location variation of the common X. helleri. That means that you can treat your fry much the same as any typical swordtails and they will prosper. What you do to prevent male competition is up to you.