Rearing Cory Fry

[Elaine2]

My Adolphi's spawned recently and about 24 fish hatched out. A few died in the first couple of days then the rest died overnight. They were in a separate fry tank, water quality was fine and I was undertaking 20% daily changes as recommended. Water temperature was 25 degrees C and I have been feeding them on Liquifry. By contrast, to date 3 babies have managed to survive and grow up in the community tank unaided.

The fish started laying eggs again a couple of days ago, then, yesterday, the Sterbai started laying eggs. I have removed both sets into a breeding trap in the fry tank again.

I would like this batch to survive, so a few questions as I am trying to work out whether I have inadvertently done something which caused problems for the previous set of fry.

1. The Adolphi's have spawned twice in about 10 days, and, as mentioned, they have spawned before, with some success. Are they spawning too often and could it be that the eggs were not as healthy as they could have been, which could have contributed to the fry dying? If so, how do I stop them breeding so often?

2. The fry tank is 8" X 16" and although I have a small filter running there is still quite a powerful current - could this have been too much for them?

The Sterbai seem to still be getting the hang of things (they have laid eggs before but only about 6) and the female was spending a lot of time trying to stick the eggs to the gravel.

Any advice welcome as so far the fish have done better by themselves than with my assistance!

Thanks,

Elaine

 

[boyneburn]

My Adolphi's spawned recently and about 24 fish hatched out. A few died in the first couple of days then the rest died overnight. They were in a separate fry tank, water quality was fine and I was undertaking 20% daily changes as recommended. Water temperature was 25 degrees C and I have been feeding them on Liquifry. By contrast, to date 3 babies have managed to survive and grow up in the community tank unaided.

The fish started laying eggs again a couple of days ago, then, yesterday, the Sterbai started laying eggs. I have removed both sets into a breeding trap in the fry tank again.

I would like this batch to survive, so a few questions as I am trying to work out whether I have inadvertently done something which caused problems for the previous set of fry.

1. The Adolphi's have spawned twice in about 10 days, and, as mentioned, they have spawned before, with some success. Are they spawning too often and could it be that the eggs were not as healthy as they could have been, which could have contributed to the fry dying? If so, how do I stop them breeding so often?

2. The fry tank is 8" X 16" and although I have a small filter running there is still quite a powerful current - could this have been too much for them?

The Sterbai seem to still be getting the hang of things (they have laid eggs before but only about 6) and the female was spending a lot of time trying to stick the eggs to the gravel.

Any advice welcome as so far the fish have done better by themselves than with my assistance!

Thanks,

Elaine

Where did you get the water for the fry tank?You must use water from the same tank as the parent's tank.The water changes must also be water from the parent's tank for a couple of weeks at least.You are lucky that any have survived.The same goes for the Sterbai,same water as parent's tank.At this stage in the game your filter is too powerful I only use a an airline running slowly for the first while.However I always hatch my cory eggs in ice cream containers floating in the parent's tank with an open airline(no airstone) running very gently.I keep them this way for a couple of weeks & then move them on to bigger containers.

Here are some of my young Adolfoi

 

[Elaine2]

Thanks for the reply. The water was from the parents' tank, though the water changes were not - that was the advice from the information I have been reading. Can make the future water changes from parental tank water. I put the eggs in a separate tank to hatch as I have tried your method a couple of times but had no success. There's actually a lot of conflicting information out there about how to raise fry so it isn't easy to know what the best approach is.

 

[Inchworm]

Hi Elaine2

True, there are a lot of different ways to raise Cory fry. In the end, there is no one way to do it. The most important factors seem to be giving them lots of clean water and plenty of nutritious food.

I never use water from the parents tank, except when originally moving the eggs. After that, it's always fresh, dechlorinated tap water at the same temperature as the fry tank. I don't use a filter for the first few weeks because the daily water changes remove unwanted debris and chemicals. An airstone to move the surface water seems to be enough.

What are you feeding your fry? Are you keeping them in a bare bottomed tank or do you use a substrate?

 

[Elaine2]

Hello Inchworm,

Thanks for the reply. The tank is bare for ease of cleaning, but that can be easily altered, and I am in the process of acquiring an airstone to replace the filter. As mentioned, I have more eggs that should be hatching in the next couple of days but the last ones didn't make it, so there's currently no fry in the tank. I fed the previous batch on Liquifry but want to get some microworms for this batch, assuming they hatch.

 

[Inchworm]

Hi Elaine2

There's nothing wrong with keeping fry in a bare bottomed tank, but it's a lot of work to keep clean. The film that forms on the bottom can be a breeding ground for harmful bacteria and must be rubbed off daily. Then too, at some point you will probably want to add sand or gravel and that can cause problems too. Several times I've lost more fry than I think I should have at that stage.

Let me suggest an alternate method that many breeders use and that I've had success with, since you seem to be losing them during their early days. Try adding a thin layer of sand to the bottom of your fry tank and, once the eggs have hatched, cover it with the squeezings from your filter. That's right, just rinse out your filter media in the fry tank. Once it has settled and the water has cleared up it will cover them. For the first week or so they will eat the microorganisms that grow in it. When you see them swimming more actively, start adding microworms and begin to remove the organic matter by agitating the water slightly during water changes. This method will let you avoid using the Liquifry that can easily pollute their environment and it will provide them with a diet that is similar to what the fry in your big tank ate at the beginning.

 

[Elaine2]

Hello Inchworm,

Many thanks for that - will give it a try. I have taken out the power filter add put in a small air filter, which is a lot gentler. Will also try and sand and filter squeezings idea and see what happens. Hopefull this batch will be more successful.

 

[Tacklebury]

Brilliant advice Inchworm, i shall be trying that with my next batch!

These fry are the hardest to keep alive!!

 

[StrontiumDog]

Hi Elaine2,

You could always fit a small sponge filter in your fry tank. You can get them for that sized tank for about £4 plus you can split the line and have an air stone in your trap. ( not your mouth I mean the breeding trap Sorry just couldn't resist that one)

 

[jelloz]

Hi Elaine2

There's nothing wrong with keeping fry in a bare bottomed tank, but it's a lot of work to keep clean. The film that forms on the bottom can be a breeding ground for harmful bacteria and must be rubbed off daily. Then too, at some point you will probably want to add sand or gravel and that can cause problems too. Several times I've lost more fry than I think I should have at that stage.

Let me suggest an alternate method that many breeders use and that I've had success with, since you seem to be losing them during their early days. Try adding a thin layer of sand to the bottom of your fry tank and, once the eggs have hatched, cover it with the squeezings from your filter. That's right, just rinse out your filter media in the fry tank. Once it has settled and the water has cleared up it will cover them. For the first week or so they will eat the microorganisms that grow in it. When you see them swimming more actively, start adding microworms and begin to remove the organic matter by agitating the water slightly during water changes. This method will let you avoid using the Liquifry that can easily pollute their environment and it will provide them with a diet that is similar to what the fry in your big tank ate at the beginning.

Hi Inch:
I just found this forum and am thankful for all the info that you share with others on this site.
I too am losing all of my Cory fry in the first week. Over the past week, the Cories in my community tank have given me the opportunity to try several new ideas that I have read about here.

Two questions, what water level do you recommend for the fry tank when they first hatch? Should this be increased later and to what level?
Thanks for your help.

 

[Inchworm]

Two questions, what water level do you recommend for the fry tank when they first hatch? Should this be increased later and to what level?

Hi jelloz

I like to use a small tank (it's 2 or 2 1/2 gals.) with the water level at around 6" for the first few weeks. This is more for my convenience in doing water changes and doesn't seem critical. Once they look like they are able to be moved without hurting them, I move them into a 10 gal., add a sponge filter, and pretty much fill it up.

I hope you'll start a thread of your own and tell us about your corys and what you've been doing with them.