Molly Fry Survival Rate...

[RZS]

Hi everyone,

My silver Molly gave birth ten days ago today, and until now, the fry I had resuced (from being eaten) - 17 of them - have been swimming and eating fine with no major signs of issue.

I've tested the water, and all the readings seem fine (ammonia 0 / nitrite 0 / nitrate ~.2), and I double-checked the heater/temp etc.

One died yesterday, and now I've found another two dead today (they died at different times today).

A thing I did notice, was that they seemed to be having trouble swimming, and their tails almost seemed "bent" making them wobble when moving (compared to the normal motion of fish, something which was not evident with the majority of the other fry in the tank).

Does anyone have any suggestions?

Also, it's a 10 gallon tank with a sponge filter, water changed roughly every week (sometimes every five or six days, but never more than a week). Currently the fry are alone in the tank.

Any help is appreciated.

 

[yvez9]

Many fry fish are deformed when they are born and it starts affecting them after a few weeks.

There's not much you can do about it.

I guess that's why they have so many fry at the same time, so nature can sort out the strongest and the weak die....

 

[RZS]

Many fry fish are deformed when they are born and it starts affecting them after a few weeks.

There's not much you can do about it.

I guess that's why they have so many fry at the same time, so nature can sort out the strongest and the weak die....

That's what I was hoping (that it was nature taking course), but this is my first attempt at actually raising any of them.

Thanks for the info.

 

[longhorn13]

i must have gotten really lucky somehow, when my molly had her fry (about 30 of them) all survived and did fine. i gave most away and the remaining 5 that i couldn't catch when i was giving them to a friend are still alive and always hungry. they're about 8 months old now. good luck with the rest of yours!

 

[BEEF11]

i raise alot of mollies and haven't ever had that problem. I do treat mine everyso often with small fish saver though.

 

[RZS]

i must have gotten really lucky somehow, when my molly had her fry (about 30 of them) all survived and did fine. i gave most away and the remaining 5 that i couldn't catch when i was giving them to a friend are still alive and always hungry. they're about 8 months old now. good luck with the rest of yours!

Thanks.

 

[RZS]

i raise alot of mollies and haven't ever had that problem. I do treat mine everyso often with small fish saver though.

Hi,

What is small fish saver?

Thanks.

 

[JustinSane]

How long have you had them? Where did you get them originally? Is your water alkaline and hard? Do you use salt?

 

[RZS]

Have you had them for long ie? Where did you get them orginally? Is your water alkaline and hard? Do you use salt?

Hi, to answer your questions....

I've had them from birth, my female adult had them (she has now been moved out of the tank, and they are in there alone).

I haven't actually measured hardness, but from my past experience with the tanks here, it is on the harder side. Alkaline tested ok, can't remember the specific result now though.

For salt, I did and have been using 1 tablespoon per 5 gallons from the getgo.

Any thoughts, and thanks in advance.

 

[JustinSane]

Hi, to answer your questions....

I've had them from birth, my female adult had them (she has now been moved out of the tank, and they are in there alone).

I haven't actually measured hardness, but from my past experience with the tanks here, it is on the harder side. Alkaline tested ok, can't remember the specific result now though.

For salt, I did and have been using 1 tablespoon per 5 gallons from the getgo.

Any thoughts, and thanks in advance.

Okay so that seems fine. Hmm. So there no other fish / only the fry has got symptoms, right?

If so, my guess would be that it's just a "bad batch" ie. something was wrong during the carrying, maybe their mother was exposed to something unhealthy, or then they've just got "bad genes". With livebearers inbreeding is very common and it usually takes time before problems arise, but it does happen, the gene pool is just (sometimes) majorly messed up because it's so small.
Though abnormal swimming might also indicate to some swimming bladder problems, but who knows? Just keep a close eye on them.

 

[BEEF11]

RZS small fish saver kills Saprolegnia which will invade the gills of small tetras and baby fishes and kill with no symptoms. mine is made by "Jungle" and they claim it is very safe. I just don't like the thought of loosing a whole net full of fry.

Brian

ps my guppie had 64 fry last night that i found thats a new record for me.

 

[RZS]

Okay so that seems fine. Hmm. So there no other fish / only the fry has got symptoms, right?

If so, my guess would be that it's just a "bad batch" ie. something was wrong during the carrying, maybe their mother was exposed to something unhealthy, or then they've just got "bad genes". With livebearers inbreeding is very common and it usually takes time before problems arise, but it does happen, the gene pool is just (sometimes) majorly messed up because it's so small.
Though abnormal swimming might also indicate to some swimming bladder problems, but who knows? Just keep a close eye on them.

There are no other fish in there with them now, but the mother (who is now in my 55 gallon community) is fine.

What I have noticed is that the fry seem to become darker in colour, unable to move their tails, and that their eyes become much darker/more full as well. It seems that they are essentially only able to move around using their fins, and then they tire out and die?

What's worse... I just re-tested everything in the water, and found one more on it's side, and another three "crashed" at the bottom of the tank, unable to move in anything but spurts. Also discovered that PH has spiked to a little more than 8 from 7.5 ish yesterday?

Any thoughts at all... this is now at emergency stages if I intend to keep them alive.

Hopefully I'm not fighting for a lost cause.

 

[RZS]

RZS small fish saver kills Saprolegnia which will invade the gills of small tetras and baby fishes and kill with no symptoms. mine is made by "Jungle" and they claim it is very safe. I just don't like the thought of loosing a whole net full of fry.

Brian

ps my guppie had 64 fry last night that i found thats a new record for me.

Hi,

Thanks for the info Brian.

I'll make a run to my LFS and see if they have it or something similar.

And congrats on the arrival of your new fry... wow all 64 of them!

 

[princeegrl]

my black molly gave birth to 21 fry two months ago since then we have five very health babies

 

[RZS]

my black molly gave birth to 21 fry two months ago since then we have five very health babies

What happened to the others?