cory fry dieing

[macky1]

i have (had) about 20 cory fry in a growing on tank
with a sponge filter and a clean bottom.
water change is every other day (10%)
temp 25C

the fish have grown from eggs and are now around 3/4 of an inch in length
but the last week i have lost 4 fish ...
i have found them lieing on there sides and swimming upside down in circles

why is this???

i did water tests ammonia/nitrite/nitrate/oxygen/cloramine/chloride
all is well

please someone help before i loose anymore corys......

i have also noticed that the darker coloured fish are the ones dieing



CHEERS
MACKY

 

[Inchworm]

Hi macky1

I put off answering your post in the hopes that someone else might come along and give you an answer that I might benefit from too.

I don't know how to answer your question, but I can tell you that I've had the same sort of thing happen with some of my cory fry. I can only tell you what I think, and what I do that seems to work for me. With luck, your fry will make it through.

I lost my entire first batch of C. sterbai fry at about the same age as yours are now. They became ill and died in the course of one day. I never did find out what caused it, but I assume that it was some kind of bacterial thing and so I do lots and lots of water changes.

I use a bare bottom tank too, and rub the bottom every few days with a plastic scrubbing pad to make sure there is no buildup of fish waste or spoiled food sticking to the bottom. I also rub the sides for the same reason, and change at least 25% of the water daily. I use a sponge filter, but less for the keeping a cycled tank than to circulate the water, since good oxygenation is important to keep the bad bacteria to a minimum.

I've never used medicine on any of my fry and since the loss of the entire batch, which was when I started more extensive cleaning and water changing, I don't seem to have more that an occasional death once they get past the tiny fry stage.

Once they get to the stage where they start getting taller as well as longer, and start filling out, I move them to a cycled tank with a gravel bottom to finish growing up. It seems that I can relax at that point, and just treat them like the rest of the fish.

I don't know if this will help you, but I hope it does. If you learn anything more specific about the causes and cure/prevention, please share the information with me.

Good luck and please let me know how things turn out.

 

[macky1]

thanx inchworm

i do the same things as you regards the set up, feeding etc

but i have been told by a few people on other forums to feed them a pea for protein, and start feeding micro worms

they say its a protein deficiancy in there diet

need to know were to get some micro worms now??


macky

 

[Inchworm]

Hi macky1

Protein is very important in the diet of cory cats. I feed my adults lots of live blackworms and sometimes live tubifex worm. And I start my fry on microworms with good results.

I don't know what a pea will do in terms of providing protein, but you could try something else. Once my fry get old enough to eat them, I give them very finely chopped up live blackworms and tubifex worms. This sounds much worse than it is. Just get a very sharp knife and chop up and down--don't mash them. A razor blade would probably do a great job.

Once they start eating these, they seem to start growing faster than before, so I start adding them as early as possible, even while continuing the microworms, which they love.

I never tried chopping the frozen ones, because I don't like the looks and smell of them and find my corys like the live food better. Tubifex are smaller and finer than the blackworms and are easier to chop into the tiny bits, but either works well.

Here's a link to a site that has lots of information about the various types of live critters available to feed fry and adult fish. It's a US site, and I don't know that you could order from them, though.

http/www.livefoodcultures.com/

Here, I think Aquabid.com has sellers of microworms too, so if there is a UK equivalent site you might find a source for them there.

If you don't use live food now, and need to know how to clean and care for it, let me know.

Good luck!

 

[NEON98101]

Once my fry get old enough to eat them, I give them very finely chopped up live blackworms and tubifex worms.
I am not certain about this but those 2 worms can be the cause. I hear those 2 worms come from the not so clean environment and they may carry some disease. So I read on some web link and forum. Although I also read that they would be fine if they are frozen or freeze dry since the process kill off all the disease. So personally I do not feed those 2 worms to my corys, adults or frys. And I can't afford the price of frozen food. So I feed my cory some mixture of flakes, pellets and krills. Which I keep them in the clean pepper grinder and grind some to my fish. You can adjust the grind size. I also feed my fish baby brine shrimp. I know the hatched or unhatched egg shells are also the suspicion of causing cory fry digestive problem so I used to feed not until they get old(big enough) but now I found out how easy to decapsulated the BS eggs and hatch. So no more egg shell for me. And nothing valify that the frys are eating and well than seeing the fry with big orange stoamech full of BBS. And I know the fry would grow well.
Yes, I do lose some fry also now and then. I usually notice the one won't make it have this hollow, concaved stoamech. And I see the skinny cory fry, I know s/he is in trouble.
I do feed the hard boiled egg yolk, this can be messy but all my fish enjoy. I also made the beef heart mix which you can find the receipe on web. Especially, cory seems to enjoy. I feed some raw meat(chopped up small to fit their mouth) without the fat occationary. Same goes the raw seafood(shrimp, white fish etc.,) And I also have vinegar eels, micro and grindel worms. And i am not really crazy about this but chopped up earthworm. It seems cory really like them. Of course, I culture them so they are not grow with pesticide. But you know what you do for your fishy.
I think it is inevitable that some fry loss do happen, some just not fit to survive. But I would try my hardest to keep my cory growing fry to have big sticked out stoamech. And they do like to eat, eat a lot. I think they would eat all day if they could. And you do have to make sure to suck out the left over and do the water change often to maintain the high water quality. I feed my breeder and growing young frys several times a day if I could. And I do change the water 2~3 times a week, about 25~60%.
I would be alarmed if I lose high number of fry in short period. Then, I suspect the water quality and/or disease. But unless you have the microscope and some knowledge of the diesease and do the autopcy, you can't be sure. And if you don't think these are not cause of your death, they just might well be they are genetically not strong enough. I may sounds harsh but not all of them make to be adults. That is why fish lay so many eggs. And also, I would consider add the new stock if I get deformed. Then I know my breeder is too closely related. You know, father and daugher, mother and son, etc.
And also, you may find better answer or solution in catfish or corydoras forum than here. Try these and there links.

WWW.*********.com
WWW.*********.com

to name a few. Well, good luck. I believe I topped out my humble opinion.

 

[macky1]

thanx for the replys chaps

the corys that are dieing are a lot darker than the others and havet he sunken stomachs that was mentioned by neon

maybe they are just the weak ones of the batch

the others look fit, fat and hungry and have a brightness to them and are very lively

i do a water change (20%) every other day and suck out any uneaten food

cheers

macky