Problems Raising Cory Sterbai Fry

[Elaine2]

I have been successfully hatching and rearing cory sterbai for a little while now. I have used the method recommended by Inchworm and others of changing 20% of the water daily and feeding them by squeezing out a filter sponge in the water. However, the last 3 or 4 batches of eggs have hatched but never grown on. I am doing the same as before, the tank is at the same temperature and pH, so I am rather at a loss as to what has happened. The only two things I can possibly think of are 1. I am using methylene blue (a very small amount) to prevent fungus developing on the eggs, previously I was using a product that contained methylene blue. Howver, I am also fairly certain that the no-show of fry started before this change. 2. When I examined the tank with a magnifying glass I spotted some incredibly small, white, flea-like creatures in the water. I may be clutching at straws here but are the latter possibly some kind of parasite that could be damaging the eggs or newly hatched fry?

Suggestions welcome as I have moved another 70 eggs into the hatching tank tonight and I'm starting to feel both very guilty towards the parents and somewhat paranoid!

 

[Harlequins]

I wonder if its worth giving the tank a clean? i gave my cory fry tank an overhaul last week,mainly to add more sand but ended up cleaning it through.

Do you use liquidfry? - this can mess tanks up pretty fast,infusoria organisms can also grow from liquidfry itself.

I've never used methane blue so i can't comment,(although i know it can mess a filter up)i tend to keep my eggs in a net over an airstone until they hatch,think i've only ever had 2 eggs from fungus,thats because i put them in with fry and ended up having food stuck to them.

 

[jelloz]

I have been successfully hatching and rearing cory sterbai for a little while now. I have used the method recommended by Inchworm and others of changing 20% of the water daily and feeding them by squeezing out a filter sponge in the water. However, the last 3 or 4 batches of eggs have hatched but never grown on. I am doing the same as before, the tank is at the same temperature and pH, so I am rather at a loss as to what has happened. The only two things I can possibly think of are 1. I am using methylene blue (a very small amount) to prevent fungus developing on the eggs, previously I was using a product that contained methylene blue. Howver, I am also fairly certain that the no-show of fry started before this change. 2. When I examined the tank with a magnifying glass I spotted some incredibly small, white, flea-like creatures in the water. I may be clutching at straws here but are the latter possibly some kind of parasite that could be damaging the eggs or newly hatched fry?

Suggestions welcome as I have moved another 70 eggs into the hatching tank tonight and I'm starting to feel both very guilty towards the parents and somewhat paranoid!

Hi Elaine: From the sounds of it, the only thing that I could think of is that maybe the filters are squeezed out so much that there is very little "food" in them anymore. Possibly your Sterbai have ramped up their production of eggs and now the food source has been tapped out.
I would try to get additional food sources for them, dried food and micro worms. That way if something goes bad on you, you always have a backup food source to go to.

 

[waxjlp]

Hello, this is my first post here.

I do spawn C.Sterbai as well. Especially, the last month and half spawning activity is so frequent. I use to have huge problems of raising the fry due to 2 reasons: 1. bacteria infection caused bloating; 2. incorrect fry food (microworm exclusively). This winter, I totally changed my method. I placed the eggs into a plastic fry box and feed almost exclusively on BBS on day 2 after hatch till week 4 or so. Success rate is fairly high. Although I did see a few dead fry out of 60-70 before week 2, I believe that was caused by lack of food or just natural weak fish. Compare to last year this time which I get 600+ eggs at one spawn and only had less than 10 left, this ss a significant improvement. I am sure there are a lot of other practices lead to success, but this one is certainly working for me.

 

[jelloz]

Hello, this is my first post here.

I do spawn C.Sterbai as well. Especially, the last month and half spawning activity is so frequent. I use to have huge problems of raising the fry due to 2 reasons: 1. bacteria infection caused bloating; 2. incorrect fry food (microworm exclusively). This winter, I totally changed my method. I placed the eggs into a plastic fry box and feed almost exclusively on BBS on day 2 after hatch till week 4 or so. Success rate is fairly high. Although I did see a few dead fry out of 60-70 before week 2, I believe that was caused by lack of food or just natural weak fish. Compare to last year this time which I get 600+ eggs at one spawn and only had less than 10 left, this ss a significant improvement. I am sure there are a lot of other practices lead to success, but this one is certainly working for me.

I also have a better success rate for 30-40 eggs at a time than 150 eggs at a time. From now on, I am going to break the 150 egg batches into tubs of 30-40 eggs and see how that works.

 

[Elaine2]

Thanks for the responses. To try and answer all of them, the tank has received a good clean recently, so will see if that makes a difference. Re. over-squeezing the filters, I run 7 tanks so don't always use the same filter, so that is less likely to be an issue, though one worth pondering. I don't use Liquifry, I generally move the fry on from filter sqeezings to powdered flake and tablets as they grow. Unfortunately, none have made it past the hatching stage for a while!

Just wondering aswell whether it may be worth trying to raise some of this batch in a net in the parents' tank as there are now well over 100 eggs in the hatching/fry tank. Advice on this method welcome as it is one I have never used e.g. how/what do you feed them? What type and size of net? How to you secure it?

Cheers,

Elaine

 

[Harlequins]

This is my set up for bringing on eggs,i use a ordinary catching net attached to the tank by magnets/clothes pegs,with an airstone underneath,not a brilliant way,but i have 99.9% hatch rate.

 

[jelloz]

Thanks for the responses. To try and answer all of them, the tank has received a good clean recently, so will see if that makes a difference. Re. over-squeezing the filters, I run 7 tanks so don't always use the same filter, so that is less likely to be an issue, though one worth pondering. I don't use Liquifry, I generally move the fry on from filter sqeezings to powdered flake and tablets as they grow. Unfortunately, none have made it past the hatching stage for a while!

Just wondering aswell whether it may be worth trying to raise some of this batch in a net in the parents' tank as there are now well over 100 eggs in the hatching/fry tank. Advice on this method welcome as it is one I have never used e.g. how/what do you feed them? What type and size of net? How to you secure it?

Cheers,

Elaine

Elaine:
You are doing the right things. Going back to your original post, you talk about a "flea" creature in the water. Those could be daphnia. They are actually called "water fleas".
http/lawrencehallofscience.org/foss/fossweb/teachers/materials/plantanimal/daphnia.html
If yes, they are good food for your fry.
The only other thing that I could think of is the methylene blue change that you made. Possibly the "new" MB that you are using is killing off the beneficial bugs from your filter squeezings.
Good Luck. Keep us posted.
JOe

 

[Elaine2]

Many thanks, folks. I gave the tank another good clean this evening to remove any remaining debris (though not so clean as to make it sterile). I have also added in my spare tank as a second hatching tank, with some sand in the bottom, and divided the eggs between the two hatching tanks. One now has a tricle filter running (which I was using before) and the other has an airstone. Will keep fingers crossed and see what hapens. A good point about the methylene blue - could be a possible reason for failure. I found some more eggs this afternoon as well so there's well over 100 in there, so hopefully some fellas will grow up big and strong this time!

 

[jelloz]

Many thanks, folks. I gave the tank another good clean this evening to remove any remaining debris (though not so clean as to make it sterile). I have also added in my spare tank as a second hatching tank, with some sand in the bottom, and divided the eggs between the two hatching tanks. One now has a tricle filter running (which I was using before) and the other has an airstone. Will keep fingers crossed and see what hapens. A good point about the methylene blue - could be a possible reason for failure. I found some more eggs this afternoon as well so there's well over 100 in there, so hopefully some fellas will grow up big and strong this time!

Good luck with the eggs. As the breeders get older, you tend to get more eggs. Also, as your skills at raising them improve, they will take up more and more space and tanks in your homw.
How many sterbai have to raised so far? Let's say past 3 weeks of age?

 

[Elaine2]

Hello Jelloz,

I've raised about 70 sterbai to date and about 15 adolphis. My first batch of eggs was a complete disaster as I tried keeping them in a bare tank and using Liquifry - then Inchworm and others gave some helpful advice re. feeding methods and having some substrate, and the success rate was pretty good over several batches. Until the last 2 or 3, that is. The sterbai seem to hatch and grown well in a fry tank, but I've had better success with just leaving the adophis to it. There's a very large clump of moss in their tank that like spawning and growing in. The sterbai have started producing silly quantities of eggs now, which is nice, but unexpected.

 

[jelloz]

Hello Jelloz,

I've raised about 70 sterbai to date and about 15 adolphis. My first batch of eggs was a complete disaster as I tried keeping them in a bare tank and using Liquifry - then Inchworm and others gave some helpful advice re. feeding methods and having some substrate, and the success rate was pretty good over several batches. Until the last 2 or 3, that is. The sterbai seem to hatch and grown well in a fry tank, but I've had better success with just leaving the adophis to it. There's a very large clump of moss in their tank that like spawning and growing in. The sterbai have started producing silly quantities of eggs now, which is nice, but unexpected.

I see on another topic that you seem to have fixed the problem. Do you know what is was? Thanks.