Corydoras sterbai eggs - moved to separate tank - questions

[Vorpal]

Hi everyone,
Our corydoras sterbai spawned overnight. I wasn't really prepared & didn't have a breeding net or anything. I do have some breeding boaxes for our live bearers, but I think the openings in those are too big for newly hatched cories.

Anyway, we had a little 30 litre (10 gal?) aquarium, unused, so I set that up with some water from the tank the eggs were laid in. I then moved the eggs to the little tank.

The only filter I have is one with an internal sponge. I used some of the media from my big tank (Eheim external filter & pump), then I put a section of pantyhose/nylon tights over it, so it wouldn't suck any eggs or fry in. I also put it on the lowest pump setting, but I'm still worried it's too much.

I was wondering about changing to a sponge filter, assuming I can buy something suitable at the moment. But then how do I build a bacteria colony in the filter media? I assume it works the same way as other filters?

Also, I put clean sand in the new aquarium. I didn't really think about it at the time. I just wanted to save the eggs form being eaten.

Is the clean sand okay? If they are fed liquid food for egg layers?

TIA

 

[Sarah73]

Hi everyone,
Our corydoras sterbai spawned overnight. I wasn't really prepared & didn't have a breeding net or anything. I do have some breeding boaxes for our live bearers, but I think the openings in those are too big for newly hatched cories.

Anyway, we had a little 30 litre (10 gal?) aquarium, unused, so I set that up with some water from the tank the eggs were laid in. I then moved the eggs to the little tank.

The only filter I have is one with an internal sponge. I used some of the media from my big tank (Eheim external filter & pump), then I put a section of pantyhose/nylon tights over it, so it wouldn't suck any eggs or fry in. I also put it on the lowest pump setting, but I'm still worried it's too much.

I was wondering about changing to a sponge filter, assuming I can buy something suitable at the moment. But then how do I build a bacteria colony in the filter media? I assume it works the same way as other filters?

Also, I put clean sand in the new aquarium. I didn't really think about it at the time. I just wanted to save the eggs form being eaten.

Is the clean sand okay? If they are fed liquid food for egg layers?

TIA

Hello, and congrats on the eggs! Not many people are ever prepared for eggs. When I had left mine in a breeder box, I regretted it as they all escaped and got eaten that day. If you don't want to cycle the 10-gallon tank, just do water changes every day. Sponge filters easily colonize on the sponge filter! Plus your fry will gladly eat anything that is on the sponge filter. Don't add sand to the aquarium until they are older or you will never be able to see them and may suck them up if you are doing water changes. Give them a bare bottom for the first few weeks until their barbels start growing and forming. What do you mean liquid food for egg layers? I give mine newly baby brine shrimp! But, you don't give them any food for the first few days after they hatch because they are absorbing their egg sack.

 

[Vorpal]

I've read that it's not good to leave the bottom of the aquarium bare. Anyway, the sand is already in the tank. Since it's clean sand, I was planning on doing water changes without cleaning the sand for at least a couple of weeks. After that I will see how it goes.

I live in Norway, and the food that is commonly available for egg-laying fry comes suspended in liquid. I buy it in a small bottle. I have never seen baby brine shrimp for sale here. Just normal brine shrimp. I can ask at the pet shop, but I'm not very confident of being able to find some.

 

[Byron]

1. You definitely want sand on the tank floor. When the fry begin swimming, they will benefit from sand. There is less (much less) risk of bacterial issues with sand as it is the bacteria bed of a healthy aquarium. Once you start adding foods a clean of the sand is advisable, but not for some weeks yet. It will be 2-3 weeks before you even see the hatched fry (at least I couldn't see them).

2. Forget about cycling. Add some dried leaves now so they can begin to break down. This not only provides good bacteria, it will provide the important first food for fry--infusoria. Use several leaves, you really cannot have too many. Dried leaves collected from the ground after they have fallen as dead leaves, from a safe site, are good, from hardwood trees (oak, beech, maple) or you can buy Indian Almond leaves in some fish stores/online.

3. Dried leaves are essential first food. All fry develop faster with leaves. You can use the prepared foods, or make your own (Colin I think has posted on this) for fry. I drop in a couple shrimp pellets once I can see the fry, it is amazing how quickly they get going on these. I've raised vrine shrimp for cichlid fry, but never cory; I doubt they could eat them. Cories are filter feeders, they primarily feeed on insects and insect larvae living in the sand, so shrimp swimming about in the water is rather a waste.

4. The sponge filter (connected to an air pump) is best. Good that you used water from the main tank where the eggs were laid; not doing this frequently results in loss of the eggs/fry.

If you have some, a chunk or two of wood from the main tank is a good idea. This is loaded with various bacteria, and microscopic live food.

 

[Sarah73]

Actually, they eat to the baby brine shrimp just like any other fish, yes they are bottom feeders, but they swim to all parts of the tank. Top, mid, and bottom. Sand isn't needed for at least the first week of a cory fry's life. Mine have bellies full with baby brine shrimp. Little pellets make the water foul.

 

[Gypsum]

My black corys spawned yesterday (I think it was them, rather than the CW045s). I moved the eggs to the hospital tank, which I filled with water from main tank. The sponge from the sponge filter has been living in my big Fluval 307 so should have plenty of bacteria. I'll add an Indian almond leaf, as per Byron's advice. Fingers crossed they hatch! Not convinced our egg-shifting from main tank to hospital tank was particularly smooth.

 

[Vorpal]

Well, I called around to various pet shops & none have sponge filters. They all said they can order them, but it's hard to say when they will arrive because their normal supply times are disrupted. I was thinking of having a go at making my own, but they didn't have any air pumps, either. Basically either the sponge filters with a a sponge in a canister, or external filter/pump systems. So, I just got some extra filter media for one of my other tanks, and I will try to modify one of them to go around the outside of the little filter pump in our nursery tank.

As for the leaves.... I have some linden (lime) blossom that I picked and washed last autumn for making an infusion with. That has leaves on it. Could I use that? I don't have a good source of other clean leaves. I can find oak and maple in the forest. Beech trees don't grow where I live. I think there are a few on the southern and western coasts of Norway, but it's too cold, here. We do have lots of birch. That would probably be my next best option.

I did transfer some aquarium plants, and a couple of additional leaves to the nursery tank, both for the ecosytem and because there were eggs on them

Those eggs probably have the best chances of all of them. I was painstakingly careful transferring the others. I took me about 2 hours to transfer 40 or 50 eggs. They seemed to all be in clumps of 3 or 4. But I am not certain that I was successful in transferring them without harming them. Some have stuck to the glass in the nursery tank, so we should be able to see them develop if they are going to.

 

[Martyn87]

I always used a little air stone and did daily water changes, be careful not to suck up fry, I used airline for my water changes.

I would get a banana worms culture untill you can get them onto baby brine shrimp.

 

[Martyn87]

Dont forget to take out any eggs with visible fungus or that look white.

 

[Retired Viking]

Would you please post some pictures when they get big enough to see? thank you.

 

[Martyn87]

Ah btw if you have a cannister filter you may find a few in there so check it on this week's water clean. I always used to find 5+ in there after I took out the bulk of eggs I could find

 

[Gypsum]

Mine might have fungus. &(&)^*(*()##

 

[Martyn87]

There's always a few that do ok. I would have like 60 plus eggs and maybe 10 from a hatch after the other fish have nibbled a few. When they used to get to 1cm long and had colour mine just went back into the community tank. Be sure to take out any runts as well.

 

[Vorpal]

Ah btw if you have a cannister filter you may find a few in there so check it on this week's water clean. I always used to find 5+ in there after I took out the bulk of eggs I could find

The mother tank has an external filter & pump. I have a bit of nylon stocking/pantyhose over the intake. I did lose a few eggs on the bottom during the removal process, but I guess those will get eaten.

 

[Vorpal]

Mine might have fungus. &(&)^*(*()##

I hope not. I hope you get a few surviours.