Platy fry questions

[canuck]

I picked up two female platies a few days before Christmas, not knowing that one or possibly both were pregnant. One of them had babies a few days later, which I separated into a little floating plastic breeding tank (probably not the correct term, I know ) that the fish store recommended.

The fry seemed to be doing fine for a couple of weeks but 3 or 4 days ago one of them died, and two more have died since then. The water tests fine and I've been feeding them crushed up flakes 3-4 times a day.

The person I spoke to at the fish store indicated this is normal. She said it's normal for only 2 or 3 fish to survive out of 10 or more babies. Is this correct?

The second of the original two platies looks quite fat, but I can't see a gravid spot. How long is the gestation period for these fish? I don't know how long they might have been pregnant at the store before I got them, but I've had them for a little over 3 weeks now and I'm wondering if I should still be expecting more little ones.

My last question is regarding adding more fish to the tank. I've got a 29 gallon tank and was planning on adding some more fish to it once the first two were settled in. Is there any problem with adding some other fish to the tank if one of the current two are pregnant? I was planning on getting a different non-aggressive breed.

 

[mandi]

First off, congrats on the fry.

If you get a chance, I'd exchange the plastic breeding trap for a mesh one with a plastic frame (they hook to the side of the tank). I've heard some horror stories about fry getting pinched "vents" in the plastic ones.

That does seem to be kind of a high number that are dying. I wish I had some good advice on that, but if the water parameters are ok, I'm not sure what it might be. I definatly disagree with the lady at the fish store though -- before I got rid of my big "mom & dad" platy, I would move the mom to a seperate 10 gallon tank to give birth, then move her back. I would have anywhere between 10-30 fry at a time typically, and I haven't lost a single one yet. (And I'm no "expert" at this by any means. Maybe it's just dumb-luck.) The only way I would say that's normal to lose that many is if they're in the main tank where other fish can eat them.

As for gestation period, I'm not really sure, but mine had babies pretty much on a monthly basis -- about every 35 days. So I'm going to guess 4 weeks about?

As far as adding more fish to your tank, you might stay away from anything too fast and "hyper" (like danios) until the platy has her fry, as all the activity in the tank might stress her out and make her lose the babies. I've never had a problem with this -- but it's the only caution I could think of. You could add somthing like some nice cute little corys with no problem though, I would think.

Keep us updated on how its going!

 

[Def]

The person at the fish store is talking crap. It is NOT normal to have 70% of your fry die. You occasionally lose 1 or 2 for various reasons, but I've had batches of fry with 100% survival as far as I could tell.

Next, take the fry out of the breeding net. Platy fry are smart, they won't get eaten and keeping them in a net will stunt their growth. Put some flake in the water at the same time as you release the fry otherwise the adults will chase them.

Gestation is 25 days or so, but it's hard to tell with platys as they store sperm and can reimpregnate themselves.

You can add more fish to that tank (depending on size etc) regardless of whether the platys are pregnant. Be aware that some fish (danios etc) will eat the fry, so base your decision on whether you want your fry to be safe or not. That said, platy fry have a way of surviving.

 

[mandi]

That said, platy fry have a way of surviving.

Agreed!!

After I got OVERRUN with platy fry, I bought some danios to help "control the population", and the lil boogers can even escape them.

 

[vidiots]

That is the main problem with platies its easy to quickly over croud with them expecially if you have more that one fertile female. I also think that mortality rate the LFS gave you is quite a bit high. It is common to see at least one out of the batch have a birth defect especially in the larger batches. It is also common for many of the fry to be eaten by the adults unless you are religious about watching the female and seperating her before she starts to give birth. I would say that if care was taken to seperate the female and the fry from the other fish and are well cared for that 70%-100% of the fry should live to adults. Some of the things to be cautious of when caring for fry if your new to it, They are small enough to get sucked into filter intakes, They like to dive down into coarse gravel and into tiny spaces when trying to hide sometimes getting themselves trapped and they will die if they go too long from the time they get stuck til the time you find them. In my fry tank I set up an undergravel filter, but instead of gravel I attached a large sheet of filter foam to the undergravel plate which is flush with all sides of the tank (no gaps) and left the fry tank otherwise completely bare. Air powered sponge filters are probably the best although I've never tried them. Watch out for power heads in the fry tank too because they don't have the strength to fight the current and will blown around the tank by them. Try not to handle them at all if you can avoid it they are quite fragile, I've injured them using net breeders and moving it and them to clean the tank. If you are trying to catch them to move them to another it is also very easy to injure them. If your using an airpowered filter, you can use the air line that goes into the filter to syphon out water through the filter durring a water change to avoid sucking the fry out with the water, because they are not smart enough to avoid your syphon.