Corry Fry Fry Dying!? Why?

[newfishaddict]

I have 12 albino cory fry. I have been feedning liquid fry food. When are they big enough to switch to baby brine shimp?

Seasons greetings

 

[Inchworm]

Hi newfishaddict

Move them up to bbs as soon as they are able to eat them. You might want to continue feeding a little of the liquid fry food for a few days, just to be sure that even the smallest are eating.

 

[newfishaddict]

My fry are dying!?

I dont know why, perhaps bacteria?(since it is happening all of a sudden I suspect infection...)

I have done daily 50% water changes. Perhaps I kept them on liquifry too long??(eggs on the 17th of december and hatched about the 20-21st of december) I just fed them some bbs for the first time just now and wow those shrip are smaller than I thought they would be....

The fry are on the bottom having trouble swimming, some apparently have died already...

I did a 55% water chang today, with treated and equal temperature water, my water temp is 24C or 75F....

 

[Inchworm]

Hi newfishaddict,

This is a terrible development!

While it's natural to expect the loss of a fair number of fry, it should happen over the entire course of their development, not suddenly like this.

First thing to suspect is, if you are using a frozen product, perhaps it is tainted. It might have defrosted and been refrozen somewhere along the line. If it even looks a little bit off, replace it with a package from a different lfs. Sf05 used frozen bbs with success, so you should not have this problem.

I don't think you can blame the LiquiFry either, unless enough accumulated in the tank that harmful bacteria is breeding in it. If you have been keeping up your daily water changes, this should have eliminated that possibility.

When fry (or corys in general) die suddenly, it's almost always related to some kind of bacterial problem, and in this case, that could only come from the feeding since they are isolated from other fish. I would keep up the water changes, perhaps dividing it into 2 smaller ones a day since the bbs are likely to spoil fast. (This is why I prefer microworms since they remain alive for some time in the water.)

As a last resort, you might want to try adding some MelaFix. This is a mild antibacterial agent. Since the fry are still so small, don't use it unless you absolutely have to. If you use it, try a half dose and make very sure it is well mixed with water before putting it in the tank.

Good luck with them. I hope they pull through.

 

[newfishaddict]

Hi newfishaddict,

This is a terrible development!

While it's natural to expect the loss of a fair number of fry, it should happen over the entire course of their development, not suddenly like this.

First thing to suspect is, if you are using a frozen product, perhaps it is tainted. It might have defrosted and been refrozen somewhere along the line. If it even looks a little bit off, replace it with a package from a different lfs. Sf05 used frozen bbs with success, so you should not have this problem.

I don't think you can blame the LiquiFry either, unless enough accumulated in the tank that harmful bacteria is breeding in it. If you have been keeping up your daily water changes, this should have eliminated that possibility.

When fry (or corys in general) die suddenly, it's almost always related to some kind of bacterial problem, and in this case, that could only come from the feeding since they are isolated from other fish. I would keep up the water changes, perhaps dividing it into 2 smaller ones a day since the bbs are likely to spoil fast. (This is why I prefer microworms since they remain alive for some time in the water.)

As a last resort, you might want to try adding some MelaFix. This is a mild antibacterial agent. Since the fry are still so small, don't use it unless you absolutely have to. If you use it, try a half dose and make very sure it is well mixed with water before putting it in the tank.

Good luck with them. I hope they pull through.

ALL my fry are dead this morning....The die off happened very fast. I changed water at 1pm and by 7pm when I awoke from a nap all the fish were dying.....Before my nap , they were apparently very healthy and swimming all about in search of food, I wonder:

1)The fry were on liquifry alone for 8 days, perhaps this was an error??
2)If I messed up my water changes somehow; I am very careful about measuring my de-chlorinator but I cant help wondering what I did wrong....
3)I did daily 40-60% water changes BUT I did skip a water changed on christmas day, I just didnt have time...could this do it? The water did seem to smell a bit "off",

ASIDE: does anyone know any disadvantages to using antibiotics when rainsing fry?Does it effect their development in any way? It seems to me that using antibiotics could have some benifit since bacterial infections seem so common...

 

[Barracuda518]

I dont think missing one water change would do that much damage. There must have been a bacterial infection that was strong enough to kill all of them. You have to remember how delicate they are, especially when they are that young. How big were the cories that spawned? Maybe they were not mature enough and the fry never fully developed in the eggs? Thats the problem with raising fry, its hard to figure out what could have happened. Im sure your cories will spawn again soon.

 

[diademhill]

How big a tank were you trying to rear them in?
For just a few fry in a normal 15-20 gallon rearing tank I would only do 10% weekly water changes ( I keep sponge filters in running in display tanks so I can pull one into use whenever needed.) even though I keep the water level down to about eight inches for cory fry.
50% changes will put a lot of stress on tiny fry.

 

[newfishaddict]

I dont think missing one water change would do that much damage. There must have been a bacterial infection that was strong enough to kill all of them. You have to remember how delicate they are, especially when they are that young. How big were the cories that spawned? Maybe they were not mature enough and the fry never fully developed in the eggs? Thats the problem with raising fry, its hard to figure out what could have happened. Im sure your cories will spawn again soon.

The corries were about 1 1/2 inches long with the female being much fatter...

They were being treated for a bacterial infection when they spawned, I suspect the pathogenic bacteria remained in the tank and easily attacked the fry....

How big a tank were you trying to rear them in?
For just a few fry in a normal 15-20 gallon rearing tank I would only do 10% weekly water changes ( I keep sponge filters in running in display tanks so I can pull one into use whenever needed.) even though I keep the water level down to about eight inches for cory fry.
50% changes will put a lot of stress on tiny fry.

Tank was 10g with only 13 fry in it, and no other fish.

I have read that when using liquifry you need to do daily water changes not weekly....

The fry were 8 days old at death....

 

[Inchworm]

Hi newfishaddict

I'm so sorry!

I suspect that your guess about the bacteria lingering might be correct. The tiny fry are so fragile and have not had time to build up strong immune systems. That's why I favor the regular water changes. I wouldn't rule out the possibility that you have a bad batch of bbs though.

Have your adults recovered? If so, I hope you will condition them and try again. I know you must be discouraged now, but you will love watching a batch grow up. And by that time you will be prepared with live food, etc.

 

[Barracuda518]

How big a tank were you trying to rear them in?
For just a few fry in a normal 15-20 gallon rearing tank I would only do 10% weekly water changes ( I keep sponge filters in running in display tanks so I can pull one into use whenever needed.) even though I keep the water level down to about eight inches for cory fry.
50% changes will put a lot of stress on tiny fry.

When the fry first hatch they are too small to add a filter. That is why you need to do daily water changes. I do 20% water changes daily to get any uneaten food out and to give them fresh water. The fry need clean water to stay healthy. I would be afraid to add any kind of filter until they are least 3 weeks old, just an air stone to add oxygen to the water.

 

[Inchworm]

ASIDE: does anyone know any disadvantages to using antibiotics when rainsing fry?Does it effect their development in any way? It seems to me that using antibiotics could have some benifit since bacterial infections seem so common...

Hi newfishaddict,

Sorry, but I missed this before. I think it's best to avoid using any medicine unless it's absolutely necessary, especially antibiotics. The reason for this is that bacteria have the ability to mutate if they are not entirely eliminated. This could result in having bacteria in your tank that will not respond to that particular antibiotic should you ever need it. While it's possible to treat them with a different antibiotic, valuable time could be lost before one is found.

 

[newfishaddict]

Hi newfishaddict

I'm so sorry!

I suspect that your guess about the bacteria lingering might be correct. The tiny fry are so fragile and have not had time to build up strong immune systems. That's why I favor the regular water changes. I wouldn't rule out the possibility that you have a bad batch of bbs though.

Have your adults recovered? If so, I hope you will condition them and try again. I know you must be discouraged now, but you will love watching a batch grow up. And by that time you will be prepared with live food, etc.

Regarding the bbs, I fed the FIRST feed of bbs when the fry were already 40-50% dead, although contaminated frozen foods do seem to pose risks I dont think they were the problem in this case....

I have 12 albino cory fry. I have been feedning liquid fry food. When are they big enough to switch to baby brine shimp?

Seasons greetings

I would really like to know how old the fry would be when they begin to eat baby brine shrimp??, as I have said I fed exclusively liquifry and only fed some bbs on their last and final day. The fry were in very bad shape and aleady dead/dying when I fed bbs for the first time...

 

[Inchworm]

Hi newfishaddict

Then, in that case it was most likely the same problem the parents had. I have never fed bbs myself, since I have an active microworm culture, but Sf05 has. I'll send him a PM and ask him to post here about his experience with them.

 

[diademhill]

When the fry first hatch they are too small to add a filter. That is why you need to do daily water changes. I do 20% water changes daily to get any uneaten food out and to give them fresh water. The fry need clean water to stay healthy. I would be afraid to add any kind of filter until they are least 3 weeks old, just an air stone to add oxygen to the water.

I've reared many batches of cory fry using a sponge filter set just below the water surface so the bottom of the tank is clear. I do water changes as needed, daily for a large batch - but 50% in one go is too risky IMO
If you are worried about the fry going near a filter you can use an air driven box filter with a layer of gravel over the floss.
I haven't used liquifry for over thirty years. Hatchling cories can eat pulped Tetra Prima as soon as the yolk sac clears but I find frozen cyclops as well as microworms are taken from a few days old.

It is a shame when you lose a batch of fry but once the parents start they usually keep on laying eggs.

If treatments have been used I would wait at least a month before attempting any rearing - who knows what effects the chemicals or the bacteria may have had on the developing embryos?

 

[newfishaddict]

When the fry first hatch they are too small to add a filter. That is why you need to do daily water changes. I do 20% water changes daily to get any uneaten food out and to give them fresh water. The fry need clean water to stay healthy. I would be afraid to add any kind of filter until they are least 3 weeks old, just an air stone to add oxygen to the water.

I've reared many batches of cory fry using a sponge filter set just below the water surface so the bottom of the tank is clear. I do water changes as needed, daily for a large batch - but 50% in one go is too risky IMO
If you are worried about the fry going near a filter you can use an air driven box filter with a layer of gravel over the floss.
I haven't used liquifry for over thirty years. Hatchling cories can eat pulped Tetra Prima as soon as the yolk sac clears but I find frozen cyclops as well as microworms are taken from a few days old.

It is a shame when you lose a batch of fry but once the parents start they usually keep on laying eggs.

If treatments have been used I would wait at least a month before attempting any rearing - who knows what effects the chemicals or the bacteria may have had on the developing embryos?

""If you are worried about the fry going near a filter you can use an air driven box filter with a layer of gravel over the floss. ""
-->I dont know what you mean when you say "a layer of gravel over the floss" ; I have seen these small air driven box filters at the store but have never used one......

I have 12 albino cory fry. I have been feedning liquid fry food. When are they big enough to switch to baby brine shimp?

Seasons greetings

I should also add:
I did notice that the corry fry had dark looking digestive tracts; is this a normal thing to see?

My adult albino corries (the ones that bred) had dark digestive tracts, it turned out that most “experts” said that was a sign of bacterial infection. Perhaps this is an indication that the cory fry suffered from the same bacterial infection….