Livebearer fry appeared from nowhere...

[AdoraBelle Dearheart]

One or more females must have had some stored sperm packets that have been used. As simple as that...
Most ovoviviparous livebearer females can store sperm packets in the folds of the fallopian tube for over a year. That goes for guppies as well. 3 Till 6 months max of sperm storage in females ain't correct what a number of sites claim to be. Most of such sites have just copied texts from a commercial book. And that have been copied the whole time. And the result is an incorrect information on the net.

Thank you!
I knew they could store sperm, but I guess I was partly hoping that they wouldn't have since they hadn't popped out any fry in previous months, and they'd never looked gravid when I watch the tank (I can usually tell when one of the girls was gravid and due to have fry, so usually knew who the mother was when a new batch of fry appeared!)
And I didn't think at least two of those females would even be able to have fry because of their deformities being so severe. That they would die trying if they did ever become gravid. But one of them must have! I don't understand how they never looked gravid though, that confuses me.

Question about the stored sperm: Can they decide when they want to use it? Like, not have any fry for 3-4 months, then decide it's the right time and use a stored packet? I also remember reading that they can choose whether to use a stored packet from a previous male, or a new packet from a new male. But I can't remember where I read those things, and don't know whether they're true. You're the perfect person to learn these things from!

 

[emeraldking]

Thank you!
I knew they could store sperm, but I guess I was partly hoping that they wouldn't have since they hadn't popped out any fry in previous months, and they'd never looked gravid when I watch the tank (I can usually tell when one of the girls was gravid and due to have fry, so usually knew who the mother was when a new batch of fry appeared!)
And I didn't think at least two of those females would even be able to have fry because of their deformities being so severe. That they would die trying if they did ever become gravid. But one of them must have! I don't understand how they never looked gravid though, that confuses me.

Question about the stored sperm: Can they decide when they want to use it? Like, not have any fry for 3-4 months, then decide it's the right time and use a stored packet? I also remember reading that they can choose whether to use a stored packet from a previous male, or a new packet from a new male. But I can't remember where I read those things, and don't know whether they're true. You're the perfect person to learn these things from!

This goes for all ovoviviparous female livebearers, they all decide by themselves when they'll release one or more sperm packets to fertilize the egss. With the exception of very young females. They can be a kind of naive and will let the whole portion of the donated sperm go through to the eggs (if they carry any).
To answer the question if such a female can deliberatley use an older sperm packet or a more recent donated one, the answer will be no. Yes, I've read it as well at certain pages on the internet. But they'll open up folds of the fallopian tube randomly. This means that one whole batch of fry can be fathered by mutilple males. Practice has also shown that this is the case.

I do have to say that there are some people who just like to be more interesting and mention that a female will use the most recent donated sperm packets in comparison to older ones. That's just not correct. If a female has already mated with more than one male and she still carries the stored sperm packets of these matings, if she'll use sperm packets to fertilize her eggs, the offspring can look phenotypically different from eachother. It must be quite a coincidence that she only uses the sperm of one male. That this does not happen very often is because if she has already opened some folds and they are empty afterwards, they are simply filled with new sperm from a new mating. If the story were true what some people claim, such a female would only use new sperm packets. But opening the folds happens randomly.

 

[Avel1896]

Your title "Livebearer fry appeared from nowhere..." almost sums livebearers up as it is proper to livebearers to appear then disappear like the Cheshire cat....

 

[AdoraBelle Dearheart]

This goes for all ovoviviparous female livebearers, they all decide by themselves when they'll release one or more sperm packets to fertilize the egss. With the exception of very young females. They can be a kind of naive and will let the whole portion of the donated sperm go through to the eggs (if they carry any).
To answer the question if such a female can deliberatley use an older sperm packet or a more recent donated one, the answer will be no. Yes, I've read it as well at certain pages on the internet. But they'll open up folds of the fallopian tube randomly. This means that one whole batch of fry can be fathered by mutilple males. Practice has also shown that this is the case.

Thank you so much for taking the time to answer this! I find it all really fascinating, and as you say, people repeat things they've heard or read on different sites, without knowing the source - I'm sure I've done that too. It's so easy for misinformation to be spread that way, and before you know it, that "fact" has just become accepted as something "everyone knows", but it's wrong. Must be frustrating to experts like you to see misinformation being spread all the time!

If a female has already mated with more than one male and she still carries the stored sperm packets of these matings, if she'll use sperm packets to fertilize her eggs, the offspring can look phenotypically different from eachother. It must be quite a coincidence that she only uses the sperm of one male. That this does not happen very often is because if she has already opened some folds and they are empty afterwards, they are simply filled with new sperm from a new mating. If the story were true what some people claim, such a female would only use new seed. But opening the folds happens randomly.

That definitely showed in my breeding experience too! I wasn't line breeding or anything, just breeding mutt guppies for fun and picking colours I liked. Started off with blue tails, and all the guppy fry were born with grey bodies. Only developing fin and body colour as they got older, beginning with black at about 3-4 weeks old, roughly.

Then I bought a blonde delta female guppy and a yellow snakeskin male guppy, first time I'd added yellow to my stock. The batches the females had from then on were usually a 50/50 mix of fry born with grey bodies, and ones born yellow.

I realise that genetics and phenotypes are way more complex and involved than that, but it was pretty obvious once fry were born and raised to 3-4 months old that the mother had used a mixture of sperm packets from the new yellow male, and the previous blue males.

Also doesn't really make sense that they'd be able to choose which sperm packets to release, since that would be a real level of complexity, and I don't see the benefit to the female, in an evolutionary sense, when clearly any male she mated with was acceptable to her. But it does make sense that they can somehow select when is a safe time to risk becoming gravid and having fry. Thanks so much again for the information