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fish_4_all 11-13-2006 08:11 PM

Ever been dooped by swordtails?
I have a few and every time I think i have identified one as a female for sure, it turns out to be a male. This has happened 6 times. The fish reach the size of their parents, no sign of a sword and no point to the anal fin and then 3 weeks later, voila, magical male!

I know some fish change sexes but I am pretty sure Swordtails aren't one of them. Just an oddity that really makes for sexing these little critters really hard until they are sexually mature, not just the size of the parents.

Lupin 11-13-2006 09:18 PM

Some male swords are quite late developers.:wink2: I'm not surprised that they are myths surrounding the swords saying they change sex which IMO is quite wrong.
I kept swordtails before and males have a tendency to develop very late.

tophat665 12-02-2006 08:35 AM

Blue, I hate to disagree with you. I'm sure I read somewhere recently that in an all female population of Swordtails, some will turn male. In that same article (and I am racking my brain trying to remember where it was) it was noted that these "late males" had a much deeper body shape than is characteristic of Swordtails that are born male.

fish_4_all 12-02-2006 01:36 PM

Well I have searched for hours on end to try and find any resource that says that female swords can change sex with no luck. I wouldn't say that mine look like females as their body is ussually a little more slender anyway but they don't develop the pointed anal fin until much later than other males do.

I would really like to see that source if you can find it tophat.

crazie.eddie 12-02-2006 02:56 PM

I have never seen any information regarding female swords changing to male swords. If it wasn't any kind research, then I would have to think that someone has observed a late blooming male.

tophat665 12-04-2006 11:03 PM

OK, I can't find the original artical, but I did some poking around and gleaned the following:

Amateur opinion breaks down into:
  • In an population with too few males, some females will change sex.
    Swordtails don't change sex, but older females develop male traits (a false gonopdium and small sword). (Come give your Aunt Bunny a kiss....:shock:)
    Some males just develop later.

Based on the one learned article I could find (and make sense of), I have to believe that the last one is the case. The reason being is that I had previously held the first opinion, and believed that the way one could tell a male that had changed sex was that it had a largely female body size and shape. Whereas this article implies that males that grow to the female size and heft tend to develop later and exhibit a sensitive, 21st century approach to mating.

So they're not transsexuals, they're metrosexuals. :squint:

Quack Ergo Duck :brow:

Lupin 12-04-2006 11:06 PM


Originally Posted by tophat665
So they're not transsexuals, they're metrosexuals. :squint:

:bluelaugh: Define them.:thumbsup: :brow:

Quack Ergo Duck :brow:
Who's he?:question:

tophat665 12-04-2006 11:31 PM

So far as I can tell, a metrosexual is a straight man who matches his socks to his ascot, and can intelligently discuss exfoliants.

QED - Quack Ergo Duck. (Quod Erat Demonstrandum - Thus is it demonstrated - If it walks like a duck and quacks like a duck, then it's probably a duck.)

crazie.eddie 12-05-2006 06:28 PM

I would still think that it may be an underdeveloped male. I guess a good experiment would be to...

1. Setup 3 or more tanks with one male and one female in each tank.
2. Allow the females to be gravid and release fry. This will CONFIRM they are indeed females.
3. Remove and place all the females in one tank
4. Remove and place all the males in one tank.
5. Examine all the fish to see if one or more will turn into an opposite sex.

I may do this in the future. I just need to get a few 10 gallon tanks and also find out who I can donate the swords to.

Lupin 12-05-2006 08:00 PM


Originally Posted by crazie.eddie
I would still think that it may be an underdeveloped male. I guess a good experiment would be to...

I agree with you, Eddie. I've had swordtails before and males just developed very late.:roll:
On the side note, my friend had a swordtail 4 years ago and her size was almost 20 cm.:blink: I nearly fainted at the sight of such a large swordtail. I'd take her but her size will only make my tank look overcrowded. The swordtail was female.:) Believe me, I visited my friend's home only once. I lost contact of him at this present. All I know is he migrated to US for greener pastures.:)

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