Results 1 to 11 of 11

Thread: Female swordtail growing tail extension?

  1. #1

    Default Female swordtail growing tail extension?

    A month and a half ago I bought 3 swordtails to act as dither fish in my CA themed tank. 1 male 2 females (based on the fan shaped anal fin, round, pregnant looking bellies, and larger size compared to the males in the tank.) However, over the past two weeks I’ve noticed the larger of my two female swordtails had started growing a tail extension and a underwent a behavioral change, chasing the other two around and even standing up to my firemouth cichlids when food was involved. He/she has never produced fry. Research on other fish forums brought up different theories like, it might be a late-blooming male pretending to be a female for a size/breeding edge, or like some saltwater fish female livebearers can change their sex in order to continue reproduction (which I have my doubts about,) the last one is due to an hormonal imbalance at an old age; females develop an swordtail and a gonopodium, and will try to breed with females like a male would but is infertile.

    Whew,

    So what the heck is going on with my “female” and what am I supposed to do, should I get more female swordtails so the other female doesn’t get harassed by both, donate him/her back to the LFS and hope they don’t pass it off to someone else as a male???



  2. #2
    Join Date
    Nov 2013
    Location
    Alberta Canada
    Posts
    259

    Default

    Just taking a guess here but I think that's a trait of the male no?
    There is something new to be learned everyday as long as we are open minded

  3. #3
    Join Date
    Feb 2004
    Location
    New Jersey
    Posts
    4,015

    Default

    That's a male. Not a female.

  4. #4

    Default

    Alright, thanks to you both. Back to the fish store with ye, now how do I avoid this mistake the next time because as I said the tail only started to grow about 2 weeks ago and he seriously looked like a female before...

  5. #5
    Join Date
    Oct 2011
    Location
    Mundelein, IL
    Posts
    399

    Default

    Quote Originally Posted by hamhock 74 View Post
    Alright, thanks to you both. Back to the fish store with ye, now how do I avoid this mistake the next time because as I said the tail only started to grow about 2 weeks ago and he seriously looked like a female before...
    You can tell by the anal fins. Pointy is male, Round is female.

    Click image for larger version. 

Name:	213393.jpg 
Views:	10 
Size:	63.8 KB 
ID:	23181
    Female, see how the fin underneath is round.

    Click image for larger version. 

Name:	swordtail.jpg 
Views:	8 
Size:	30.9 KB 
ID:	23182
    Male, see how the fin is just a point.

  6. #6
    Join Date
    Feb 2004
    Location
    New Jersey
    Posts
    4,015

    Default

    Quote Originally Posted by hamhock 74 View Post
    Alright, thanks to you both. Back to the fish store with ye, now how do I avoid this mistake the next time because as I said the tail only started to grow about 2 weeks ago and he seriously looked like a female before...
    When they are born the look like females. The males develop after a few months. Its tough to tell on young fish. Some males develop later than others.

  7. #7
    Join Date
    Oct 2011
    Location
    Mundelein, IL
    Posts
    399

    Default

    Yep, that's why anal fin is the best way, you can tell from birth if you have good enough eyes!

  8. #8

    Default

    Thanks Convict84 and Heyguy again, when I went to scoop out the male I had a chance to compare the anal fins and man do I feel silly... Like full derp, it was smack dab in front of me the entire time. I thought anal fin is the layman's term for cadual fin.

  9. #9
    Join Date
    May 2007
    Location
    Benton Harbor, Michigan
    Posts
    1,964

    Default

    Convict84 is wrong, you cannot sex them at birth, the anal fins of young are all the same. Male swords can develop their sex as late as a year and a half old;because they keep growing until they sex, these will be the biggest males. One of the reasons for so many small swords in shops is that they used to leave the smaller males in the ponds in Florida thinking they would "grow up". This resulted in early/undersized males doing most of the breeding in the ponds, producing smaller fish overall. When I was raising my own Swords, I never used a male that developed before 9-10 months of age for any breeding projects. Early males were fished out and used to feed the Cichlids!

    The way to identify females is not just the rounded anal fin, but the dark area above the anal fin, what some call the "pregnant spot". It gets larger when they actually are pregnant, but unsexed fish do not show this at all. If you have a "female" with no black area, it may not be a female. There are some strains where this does not get the dark color, but someone who is familiar with the fish can still identify the presence of the spot.

    Very old females will sometimes appear to change sex, but in reality they are not functional. If you have a "male" that shows the black "Pregnant spot", it is likely one of these old females.
    Happiness may be the door to Heaven,
    But Pleasure is not the Key.

  10. #10
    Join Date
    Oct 2011
    Location
    Mundelein, IL
    Posts
    399

    Default

    I raised them for years and you can tell from just a week or two after they are born. Just Born is an exaggeration but pretty much the same. A couple weeks is nothing.

  11. #11
    Join Date
    May 2007
    Location
    Benton Harbor, Michigan
    Posts
    1,964

    Default

    For one thing, at two months after they are born, they still don't have a sex. The sexes of Swordtails are not always determined by chromosomes because they've been crossed with maculatus platies too many times. I've selectively bred and studied the genetics of swords for more than a decade, and I can say unequivically that, if you thought you could sex them at two weeks, you were mistaken. I also know experts who worked with Swordtails for over 30 years, and they never made the claim you have made.

    Even if somehow you can magically determine the sex of a two week old fry, no one else can, so telling people that it's possible is poor information.
    Happiness may be the door to Heaven,
    But Pleasure is not the Key.

Similar Threads

  1. Where to buy Clear plastic Vacuum Extension?
    By lucky777 in forum Do It Yourself
    Replies: 2
    Last Post: 03-04-2013, 01:58 PM
  2. Growing up...
    By DoctorV in forum Malawi Cichlids
    Replies: 7
    Last Post: 09-10-2009, 03:38 AM
  3. Growing
    By adamd85 in forum African Cichlids: General
    Replies: 4
    Last Post: 10-25-2006, 08:48 PM
  4. Growing???
    By cathyhill in forum Tanganyika Cichlids
    Replies: 30
    Last Post: 08-25-2004, 08:22 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •