Do livebearers always have the whole drop at once?

[CalmedByFish]

I recently got platies. Two have given birth so far.

Guppies and endlers seem to have their whole drop in as long as 12 hours, start to finish.

But I'm pretty sure my platies will have a single one. Then a day or so later, give birth to the majority. Then another day or two later,  push out a straggler. 

I've heard that least killifish will have babies in slo-mo, but platies?

[Tihshho]

I believe it depends on the clutch size and how experienced the female is. If the female has a dozen babies they might come out a bit slower, where has if she's pressed to the gills (couldn't help the pun) with fry they might just pour out at once. 

[Guppysnail]

I have had guppies drop all at once, some here some there, and a few that dropped for just shy of two days and one that dropped 4 fry and three days later dropped the rest all at once. 

[CalmedByFish]

On 9/17/2021 at 6:57 PM, Guppysnail said:

dropped 4 fry and three days later dropped the rest all at once. 

That 3 day gap is particularly interesting.

It also occurred to me that perhaps some of the half-grown females are having drops of just a couple babies. That could be what I'm seeing... though I don't think so.

[Keeg]

It depends on the female like what @Tihshho said. Ive had guppies that could only give birth and then die, other plop out dozens of batches, ranging from taking an hour to a couple days. 

[Guppysnail]

On 9/17/2021 at 8:16 PM, CalmedByFish said:

That 3 day gap is particularly interesting.

It also occurred to me that perhaps some of the half-grown females are having drops of just a couple babies. That could be what I'm seeing... though I don't think so.

Perhaps they are younger and dropping infertile eggs with their drops I have seen that. I also had 1 weird girl who would drop a fry and eat it repeatedly then drop several not fully developed fry. She ended that session with 3 fry alive and well. I always guessed something may have been wrong with the batch or she stressed about something and dropped prematurely.  The rest of her future drops were large and she didn’t eat them. But that’s just a guess. 

[PineSong]

Interesting. I saw ONE platy fry* in my community tank the other day, and the female was just swimming around as usual. I thought for sure there would be more by now and I can't be certain there haven't been and they got eaten, but mom fish still looks ready to burst so it's hard to imagine she birthed many fry and still looks so square.

 

*Assumed platy. Only other females in the tank are white clouds so it's possible but less likely that a white cloud fry hid successfully long enough to become that size.

[ARMYVET]

On 9/17/2021 at 8:50 PM, Guppysnail said:

Perhaps they are younger and dropping infertile eggs with their drops I have seen that. I also had 1 weird girl who would drop a fry and eat it repeatedly then drop several not fully developed fry. She ended that session with 3 fry alive and well. I always guessed something may have been wrong with the batch or she stressed about something and dropped prematurely.  The rest of her future drops were large and she didn’t eat them. But that’s just a guess. 

Even fish enjoy good fresh SUSHI!  🍱🥢

[gardenman]

My understanding is that livebearing fish are different from mammals in that they just retain the eggs internally but there's no placenta or umbilical cord or anything the parent fish does to support the eggs other than holding them internally. The eggs develop and hatch just as they would if they'd been scattered. An old pet shop owner (Maryanne from Mantua Tropical Fish and Pet Island) would do c-sections (of a sort) on any pregnant livebearers that had died to remove the fry/eggs and raise them. With fish that lay their eggs externally and we can see them, we expect them to hatch over a period of a few days. The same thing happens with eggs carried internally. They hatch and then pop out when ready. 

[ARMYVET]

On 9/18/2021 at 9:04 AM, gardenman said:

would do c-sections (of a sort) on any pregnant livebearers that had died to remove the fry/eggs and raise them.

Wow now thats going the extra mile.  

[Tihshho]

That's pretty common for the competition guppy breeders. A family friend who competes had told me about this when he would get imports in to work on. If a female had passed in shipment and was gravid he'd extract the babies/eggs and artificially raise them in a DIY tumbler. Long ago, I heard of a selectively bred strain that could only be achieved by c sections, but once that information became public the strain started to fizzle out of the hobby, I'm sure if you look into it you'll find information about it on some Guppy Club newsletter from 20-25 years ago. If I remember correctly it was a short body variety. 

[CalmedByFish]

On 9/18/2021 at 4:49 PM, Tihshho said:

If a female had passed in shipment and was gravid he'd extract the babies/eggs and artificially raise them in a DIY tumbler.

That makes me wonder how long the eggs can stay alive after the female dies. The topic is kinda disturbing, but from a medical angle, intriguing. 

[Tihshho]

On 9/18/2021 at 7:27 PM, CalmedByFish said:

That makes me wonder how long the eggs can stay alive after the female dies. The topic is kinda disturbing, but from a medical angle, intriguing. 

Agreed, gruesome yet intriguing topic. I wouldn't think eggs would last long in the corpse of the female. Between a boom in bacterial growth on the body and lack of oxygen the eggs probably need to be removed ASAP once the female passes. 

[CalmedByFish]

On 9/18/2021 at 6:42 PM, Tihshho said:

 lack of oxygen

I thought that by carrying their eggs, livebearers were just providing shelter. They provide more than that?

[Tihshho]

On 9/18/2021 at 8:22 PM, CalmedByFish said:

I thought that by carrying their eggs, livebearers were just providing shelter. They provide more than that?

I'm pretty sure they would have to provide oxygen, otherwise the eggs wouldn't develop. I'm no ichthyologist though. 

[CalmedByFish]

On 9/18/2021 at 7:34 PM, Tihshho said:

I'm pretty sure they would have to provide oxygen

I guess even bird eggs need access to air, now that I think about it. 

[gardenman]

On 9/18/2021 at 5:49 PM, Tihshho said:

That's pretty common for the competition guppy breeders. A family friend who competes had told me about this when he would get imports in to work on. If a female had passed in shipment and was gravid he'd extract the babies/eggs and artificially raise them in a DIY tumbler. Long ago, I heard of a selectively bred strain that could only be achieved by c sections, but once that information became public the strain started to fizzle out of the hobby, I'm sure if you look into it you'll find information about it on some Guppy Club newsletter from 20-25 years ago. If I remember correctly it was a short body variety. 

It's a good way to save on your investment. I was a teenager when Maryanne was doing it (I'm 62 now) so that was around fifty years ago when she was doing it. It's not something you hear of a lot, but it does get done. It's  easier with bigger livebearers, but it's doable with any.

[Colu]

On 9/18/2021 at 2:04 PM, gardenman said:

My understanding is that livebearing fish are different from mammals in that they just retain the eggs internally but there's no placenta or umbilical cord

If I remember rightly Goodied fry have an unbilical cord 

[gardenman]

On 9/19/2021 at 5:57 PM, Colu said:

If I remember rightly Goodied fry have an unbilical cord 

They also have very large fry and far fewer at a time. Instead of an umbilical cord they have a trophotaenia that nourishes the fry internally from the mother. A very large fry count for a goodied is 10 to 15 compared to upwards of a hundred fry for some other livebearers. You really couldn't do a c-section on a goodied unless the fry were very, very advanced. On the more typical livebearers you can do it much earlier. Not many people keep the goodieds though. They aren't a very common fish among aquarists.