Overwhelmed with Swordtails - help!

[Fox46]

I bought 5 females and 1 male during March. I thought that would be a harmonious tank, and in the past with other livebearers, the rate of expansion has been slow and manageable since most young fry were eaten by the others in the tank (Corys, Platys, Black Widow Tetra). I learned later that sexing is an inadequate science with Swordtails and the current state of play is that a further 2 have developed into males and now I have an explosion of young fry which are not being eaten and I can see the female adults are not yet done. I've had to set up another holding tank into which I've put the three known males and into which I can put other males as soon as it's possible to sex them. But I'll need to get rid of the majority of the new stock and I think an lfs on the other side of Dorchester will take them. Is there a minimum age at which it's more humane to subject them to being fished out and transported to another home?

 

[emeraldking]

There's no specific age to move those fish to another place. On the other hand, most stores would like to have juveniles or adults. They're not always keen on very young fry. And yes, it seems that your swordtails will leave those fry alone (just like mine) that will result in an excessive population. I would go to this specific store and ask at what age they would like to take those fish in...

 

[Fox46]

I just rang them and they're happy to take both the male adults and any young fry I can catch. That shouldn't be too difficult, I can't do a waterchange without a few taking a helter-skelter ride into the bucket. I think I'll be doing a few more trips besides this one before I've managed to remove the legacy of these three males. It's odd that it was so sudden (over a period of a few days) as they've birthed two or three times so far but with only 3 or 4 surviving each time. This last batch is at least 25. Thanks for responding.

 

[Back in the fold]

Here’s your chance to break into the Swordtail business .

 

[emeraldking]

I just rang them and they're happy to take both the male adults and any young fry I can catch. That shouldn't be too difficult, I can't do a waterchange without a few taking a helter-skelter ride into the bucket. I think I'll be doing a few more trips besides this one before I've managed to remove the legacy of these three males. It's odd that it was so sudden (over a period of a few days) as they've birthed two or three times so far but with only 3 or 4 surviving each time. This last batch is at least 25. Thanks for responding.

Good to know that they're also accepting the very young ones. For not all stores will do that.

 

[Back in the fold]

Good to know that they're also accepting the very young ones. For not all stores will do that.

I haven’t seen fry for sale in any shop in decades and that used to be common .

 

[TwoTankAmin]

When I set up my very first tank I had swordtails and had not yet learned about livebearer math. However, I soon learned that angelfish love swordtail fry for breakfast, for lunch and for dinner. So I procured my first angels, 5 double dark blacks.

And then I learned that angels, once they pair off, can produce 500 eggs in a spawn which taught me why I did not want to breed angels.

Today I have learned that pretty much all fish, given the chance, want to spawn, especially in my tanks

 

[anewbie]

One difference between guppies and swordtails is that swordtails fry will hide low if they need to; i've never seen a guppy hide low. I once had coarse substrate and female swordtail spent hours chasing her fry but they would dart under the stones and she couldn't get them

So you need a low hunter for swordtail frys oddly - most hunters look high...

also swordtails are one of those weird species where females can become male - in a sense you are better off with fewer females as less frys are produced

 

[Fox46]

When I set up my very first tank I had swordtails and had not yet learned about livebearer math. However, I soon learned that angelfish love swordtail fry for breakfast, for lunch and for dinner. So I procured my first angels, 5 double dark blacks.

And then I learned that angels, once they pair off, can produce 500 eggs in a spawn which taught me why I did not want to breed angels.

Today I have learned that pretty much all fish, given the chance, want to spawn, especially in my tanks

I've only been fishkeeping for 5 years and I've had a very lucky run with mixed sex livebearers up until now. I had Platys, and when they spawned I was delighted (I can hardly believe that) but seldom more than 5 fry survived each time. And the first couple of times the Swordtails spawned the same thing happened and I foolishly believed this would continue to be a self-limiting exercise. Now the tank is teeming with them in the space of three or four days and I can tell more are on the way.

 

[Fox46]

One difference between guppies and swordtails is that swordtails fry will hide low if they need to; i've never seen a guppy hide low. I once had coarse substrate and female swordtail spent hours chasing her fry but they would dart under the stones and she couldn't get them

So you need a low hunter for swordtail frys oddly - most hunters look high...

also swordtails are one of those weird species where females can become male - in a sense you are better off with fewer females as less frys are produced

I agree, they do tend to hide low. But with this batch it's as though they know they won't be eaten, they're brazenly up near the surface, mobbing. I've removed some tank furniture, and cut down on feeding but I think they're laughing at me. Tank cleaning is a nightmare, they're everywhere! My Corys aren't interested in them and my BWT is too old to do anything but even he is looking a bit cheesed off with them.

 

[GaryE]

Stores take fry as fish food, unfortunately. But if you grow them overcrowded, they end up as compost. You can't win with overpopulation in fishtanks. Either the tanks crashes and they all die, or many of the fry face an uncertain future. Until the males have swords, they don't sell well.

 

[Fox46]

Stores take fry as fish food, unfortunately. But if you grow them overcrowded, they end up as compost. You can't win with overpopulation in fishtanks. Either the tanks crashes and they all die, or many of the fry face an uncertain future. Until the males have swords, they don't sell well.

OMG! In any event, nature has taken its course to an extent and I think the latest spawning is now down from about 30 to around 10. It's just about manageable now that I've extracted the 3 males, I just need to keep on top of identifying males in the first tank and extracting them to join these 3. Then I'll funnel some of each off to the lfs. Thanks for that info, I didn't know that.

 

[gwand]

Gary E always delivers good news!

 

[emeraldking]

i've never seen a guppy hide low

Guppy fry can also hide low (check my place...) but yes, most will choose the surface instead...

 

[emeraldking]

also swordtails are one of those weird species where females can become male

Yes, you're right that the ability of specific swordtail females can create a sex change for they are born with both male and female sex gonads. But this means that not all females have this ability.

To those who are more interested , I hope the following explanation can shed some light on this:
There is an autosomal locus with two alleles, A and a, which affects sex determination in XX fish. If the genotype is AA, the fish will be female, and if aa, the XX individual will be male. Aa genotypes are predominantly female, but sometimes (approx. 5% during the researches) such fish develop into males (Kallman, 1984)". It has turned out to be the same in other kinds of swordtails. Which explains the sex change in swordtails. And as far as experience have shown, these transformed females will become complete functional males.
if this isn't the case, the Z sex chromosome which certain females have beside the X chromosome can also be of influence in sex change from female to male.

But in swordtail breeding forms, if those are a result of swordtail x platy influence, a female with both sex gonads, can change into a male acccording to what's been mentioned above or how it works in platies. For wild platies have besides the X and Y sex chromosome also the W sex chromosome. So, breeding forms that have platy influence can also have a sex change according to how it works in platies. That depends ofnwhich part of species influence is stronger. This goes also for platy breeding forms which are a result of platy x swordtails. Swordtail breedings forms that are a result of a mutation which is further linebred (so, with no influence of platy species), the determination of XX fish of such a strain go as in wild forms (same goes for a platy strain that is linebred from a mutation).