Animal Stories - Swordtail Fish

Animal-World Information about: Swordtail Fish

   The most popular fish next to the Guppy is most certainly the Swordtail!
Latest Animal Stories
Joe - 2011-10-23
Two of my female swordtails had their fry about 2 months ago. How long before I can notice if the fry are male or female? When does the male start developing their swordtail? Joe

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  • Charlie Roche - 2011-10-24
    It could take over a year before you know the sex, They reach sexual maturity around 2 years old. Interesting thing (I thought) that I found is that usually only one male in a group will “sex out” or develop a huge tail. Sometimes two will but usually only one will mate with the females. Most times the other males do not develop the swordtail. It was said that if you remove the male with the sword from the group that another male in the tank will develop the tail sometimes in just a few weeks.
  • Rick - 2012-04-11
    I can usually spot which sex mine are at 3 months old. The males will be starting to develop their gonopodium and some also become more aggressive, dancing around a female or nipping another potential male. Females generally will have a rounder belly and only one anal fin. The late blooming male can fool many people because he often appears female and turns out later to become a big male. These are considered the 'prize' males.
valerie - 2012-03-01
We have some 3 month old fry red sword tails and we were wondering how long till we will start to see the tails on the males. The guy at the pet shop says about 2 months old....really, because if this were the case I have a tank FULL of females :/

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  • Jeremy Roche - 2012-03-02
    It normally takes longer then that to grow the actual sword. Check the gonopodia. The gonopodia is the fin on the underside of the fish. Females will have rounded fin and male will have a thin longer fin pointing to the rear.
J_H - 2011-12-21
Hello, I have 2 female black swords. I was wondering if I put them in with my 3 orange male swords and 6 orange females will they breed or should I get a black male?

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  • nm123 - 2012-01-10
    There is a good chance that they will cross breed but I would reccomend getting a black male swordtail
Katie - 2010-04-07
I have had a tank with Mollies and Platies set up for about five years. Of course they have bred well over the years and it has always been interesting to see what will come from them. A few months ago I started to notice that some of the younger males were sporting what looked like a swordtail. I have often seen these fish in the pet store, but I have never bought one. Is it possible that through their interbreeding they have created the swordtail? It's very difficult to tell if they are from the Mollies or the Platies.

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  • nm123 - 2011-11-11
    Yes if one of the fish bred with a swordtail before you got it.
Nick - 2010-05-24
I'm about to buy some platies any advice please on breeding and caring?

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  • nm123 - 2011-11-10
    just type in platy care on the internet
Ms B - 2011-08-05
My male swordtail looks like hes going to Blow UP. He looks like a Turkey What happened?

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  • Charlie Roche - 2011-08-06
    Check out Fish Disease and Treatment on Animal World - look at bloat.
Joe - 2011-07-26
Can different types of swordtails interbreed with each other? I have 4 different types of swordtails?

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  • Charlie Roche - 2011-07-26
    Sword tails do cross breed and people do it. Let them enjoy who they love......
Joe - 2011-07-26
One of my female swordfish started having live bearers about 4 hours ago. How long should I keep the female in the breading net? She still seems to have blackness around her fin? I don't want her to start eating the young?

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  • Charlie Roche - 2011-07-26
    As soon as you believe she has had all her young, pull her. Maybe having the young keeps her busy and as soon as she is done - hungry.
Mukman - 2010-07-11
Hi..I've got 2 questions..
(1)Do some female swordtails have a small "sword" at the end o their tails.
(2)I have 5 swordtails, 2 red males, 2 red females and a black and white dotted male. I got to know that swordtails are peaceful fish. But my swordtails ripped the tail off 1 of my male guppy, almost killed my goldfishes and attack all my other fishes except my betta. Can you tell me why?

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  • Ian chow - 2011-01-24
    Females do have swords and develop a gonopodium when they reach their full lifespan however. They never truly change sex.
  • CJ - 2011-04-02
    Females do not develop gonopodiums. It's possible that what you thought were females are actually males that developped late. If it remains just a very small point then its probably a female but if it keeps growing you have males my friend. The same thing happened to me.
  • Anonymous - 2011-07-21
    Your 2nd question is the one I can answer: IT'S BECAUSE YOU have more males and when that happends your male swordtails will display aggresion to other fishes in your tank to show dominance. Try ading 2 or more females in your tank.
  • Anonymous - 2011-07-21
    Oh my first reply was not correct. It's suppose to be more male than female. I typed it wrong.
lulu - 2008-11-10
Can someone help me? Both of my swordtails are sitting at the bottom of the tank and will only move if I hit the tank. At first they wouldn't stop moving and now I don't know what's going on. Oh, and the rest of the fish are perfectly fine. If there's anyone with an answer, please comment back.

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  • victoria - 2010-03-14
    I think you should check if they are spawning because female sword tails like to be really lazy when pregnant because they get really fat and weigh more when pregnant so they just sit around but
    still eat. But if they are not eating I could find out the problem.

    Just comment me.
  • Paul R. Pedigo - 2010-07-10
    Lulu, it's been my experience with them that they like to hang out at the bottom of the tank and school there. I have a ten gal. with a hybrid female swordtail, two female marigolds, and one male marigold along with a otto cat and four zebra danios. My swordtails like to hang out near the bottom in the plants. Hope this helps you out.
  • Mary Fernengel - 2011-05-25
    I woke up this morning and can't find my female red velvet swordtail fish. The male is sitting at the bottom and wouldn't come up to eat.