Is It Cruel To Separate Guppies?

[Teri]

One of my female guppies had a load of babies on Monday, last time any of them had any fry, only 8 survived, which is a number I can cope with, but i've just tried to count the new batch, and I think there around 35.
My tank is only 100litre, and i also have 6 adult guppies, 8 young guppies (around 5 weeks old) 3 cories, 3 loaches and 3 white clouds, so I am obviously well over stocked.
I have a spare tank that I'm planning on using, and I'm thinking that if I could separate the male and female guppies, there wouldn't be any more little guplings coming along, and overpopulating my tank.
however, I have a few questions.
Would the male guppies get frustrated if there were no females around? (one of mine is already trying it in with my albino cory!)

Is there a way of sexingthe fry? Even the 5 wk olds all look the same at the moment.

What age can the young ones start to reproduce? Are the 5 week old ones likely to start producing fry of their own any time soon?

 

[modaz]

he will be fine a seperate tank, thats what ive had to do, mind you they dont care what they try to mate with, dirty sods they are
fry start to show their sex at about 8weeks onwards and they shouldnt breed until they are sexual mature enough so you should be ok for now

 

[fishboy619]

not sure about this one, but if all the same sex groups are kept, then the leader of the group will change sex and breed!?
also guppies store sperm, so you will get a few batches of fry after seperated.
dont worry about the male, all male guppies breed with anything, lol

 

[nmonks]

not sure about this one, but if all the same sex groups are kept, then the leader of the group will change sex and breed!?

Sex changes do not happen in livebearers. It's a myth. Scientists have looked -- hard -- for a way to get swordtails to change sex and they don't. At most, female-looking males take a while to develop their swords, but they were always males and always will be males. The only aquarium fishes were sex changes are likely to happen are among marine fishes, particularly wrasses, anemonefish, and groupers.

also guppies store sperm, so you will get a few batches of fry after seperated.

No, they don't store sperm. What *some* female livebearers do is called superfetation, which is dividing batches of fertilised eggs into some that develop normally and others that are "put on ice" for a while, and only allow them to develop weeks or months later. Heterandria formosa, the dwarf mosquitofish, is the mistress of this particular art, and is able to divide up each batch of embryos into as many as seven batches. Guppies and mollies seem to be able to divide up a batch of embryos into two or three groups at most. In other words, the idea that once pregnant a molly or guppy will use sperm from that mating forever is nonsense; usually, after the second batch, she'll be "clean" and ready for a new male.

Cheers, Neale

 

[NoRp]

i brought 2 females and had them in there ow n tank
they have both droped 3 times and are getting preg again
so 2-3 times is not correct.

 

[nmonks]

They aren't getting pregnant again. That's the point: they get pregant just the once, but not all the embryos develop at the same rate. So some embryos develop quickly, others later on. But after a few months they will have to mate with another male again.

Cheers, Neale

i brought 2 females and had them in there own tank they have both droped 3 times and are getting preg again so 2-3 times is not correct.

 

[Teri]

not sure about this one, but if all the same sex groups are kept, then the leader of the group will change sex and breed!?


Really!!!!!!!! Ugh!!!!

I knew about the sperm storing, but they have to run out eventually!!!

 

[fishboy619]

i know that livebearers cant store sperm forever, i was meaning storing it for the next few batches of fry, my female platy was with a male for a while, then with only a group of females, had another 4 batches. so whether they store sperm, or break up the eggs into clutches, either way, not all fry will be born at the same time from one male.
i didnt know that the sex changing thing was a myth, i wasnt sure, but ive heard on different account its happened, but who knows.swordtails might not change sex, but will platie and guppies?if the scientist have only tested on swordtails, then its not conclusive evidence

 

[nmonks]

They don't. Nor do elephants. Or parrots. Or clams. Or spiders. We don't need to test them. They just don't. Changing sex is a BIG DEAL with any animal, especially a livebearer. In fact, I can't think of any livebearer -- fish, bird, reptile, amphibian, or mammal -- that changes sex. Not only would such an animal need to switch fromn producing sperm to producing eggs (or vice versa), it would also have to gain (or lose) the equipment for supporting the embryos inside its body.

All the accounts of livebearers changing sex come from aquarists, and they all sound like "I read that swordtails change sex". No-one ever says "My swordtails changed sex". So it's whatever the aquarium version of an urban myth is called.

The difference between storing sperm and delaying the development of embryos into batches might not seem much, but it's actually fundamental to the biology, and worth knowing. Learning is good, and understanding how livebearers work is what makes them interesting, especially if you get into the "rare" livebearers that do all kinds of weird stuff like have the embryos within the ovaries eat eggs or one another (sharks, some halfbeaks) or have true placentas much like ours that 'feed and water' the embryo from the mother's blood supply (goodeids).

There's also a practical element: each successive batch of fry from the one mating is (usually) smaller. So if you want to keep getting large broods, you want to put the female to the male regularly, rather than wait until she's "run out of babies".

Cheers, Neale

i didnt know that the sex changing thing was a myth, i wasnt sure, but ive heard on different account its happened, but who knows.swordtails might not change sex, but will platie and guppies?if the scientist have only tested on swordtails, then its not conclusive evidence

 

[Teri]

Complicated....but interesting. I wish the fish guide I bought gave that much info..all it said was that guppies are easy to breed, but didn't go into details, and seemed to imply that most would be eaten anyway.

So once they've had one batch of fry, and waiting to develop(?) the next lot, will the gravid spot be showing?

 

[modaz]

Complicated....but interesting. I wish the fish guide I bought gave that much info..all it said was that guppies are easy to breed, but didn't go into details, and seemed to imply that most would be eaten anyway.

So once they've had one batch of fry, and waiting to develop(?) the next lot, will the gravid spot be showing?

if she is expecting again you should see her start to swell within a week, gravid spot always there in females unless their black in colour ofcourse

 

[Teri]

Also, is it possible then for one female to be pregnant with 2 males at the same time? My first group of babies seem to be a mixture of black and yellow..the mother is black, and I've only ever seen my black male show her any attention, but I do have a yellow male in the tank too

 

[modaz]

yes it is possible but it really depends on what colour genes the female has as well. what colours does she have?
just realized shes black

 

[nmonks]

Not sure about this. Perhaps they can be fertilised by multiple males. On the other hand, some strains of fancy molly won't breed true, so it is entirely possible to have parents one colour and babies of another. Getting strains of molly (or any other fish) to breed true is quite difficult, and one of the challenges to creating your own variety.

There are some lovely books about livebearers, and I'd heartily recommend reading one. There is a lot more to these so-called easy fish than meets the eye.

Cheers, Neale

Also, is it possible then for one female to be pregnant with 2 males at the same time? My first group of babies seem to be a mixture of black and yellow..the mother is black, and I've only ever seen my black male show her any attention, but I do have a yellow male in the tank too

 

[Teri]

if she is expecting again you should see her start to swell within a week, gravid spot always there in females unless their black in colour ofcourse
[/quote]

ohh......I have so much to learn!!! I thought the gravid spot only occurred if the fish was pregnant. "mum" to the new batch doesn't seem to be showing much of one at the moment,(its very faint) but she was before they were born