To many Bronze Corydoras fry or not.

[Yellowtail]

Good day from South Africa.

Had my Bronze Corydoras spawn in breeding setup 16 day ago resulting in over 200 + eggs been laid. The eggs hatched 3 to 4 days later and I lost about 30 eggs to fungus.

Now here is my delema. Counted the fry last night and came to around 159 give or take. Currently I still have them in the breeding tank 18" 12" 12" and planning to move them to a 40" 20" 20" around the 4 to 6 weeks of age. Currently feeding Microworms and fry food 4 times a day. I do a 50% water change every second day.

If I try to grow out as many fry will the risk be that I will end up with fry that is weak or stand a chance of losing lots because of the amount of fry competing for food. Should I rather cull have of the fry to ensure a better quality fish and better servival rate.

[Bas Pels]

If you don't have the capacity to give the fishes what they need, and some 150 Cordoras @ 1 inch (that is, a sellable size) will require more than a 40 inches, or 1 meter tank, I think you better reduce the amount of fishes to what you can raise

I would estimate with your water changing of 50 % every other day, some 100 will be possible, but not much more

[Narwhal72]

I actually raise that number of cory fry in much smaller tanks. I let them grow until they are about 10-15mm long (SL) and then I start culling out any deformed, undersize, and generally unhealthy fry. I then raise them until they are market size in 10-15 gallon aquariums (about 40-50 per tank).

With my albino's I don't generally have to do a lot of culling. Undersize fish seem to be the most common with them.
With my longfin aeneus I have to do a lot of culling. Curved spines, fish not swimming properly, undersize are major issues with them because they are so inbred.

I feed microworms for the first week and then switch to enriched baby brine shrimp for the next month. At about 3 weeks I start adding in Repashy Spawn N Grow (a gel food).
Andy

[Yellowtail]

I do have a 120x60x50 cm standing empty. Depending on how many is still alive after 4 to 6 weeks and how many sick and lam I have to cull I can always split them between the two tanks.

[bekateen]

I do the same as Andy, although on a temporary basis I've allowed their numbers to be closer to 100 in a 10 gal. (then I thin them to two tanks). I raise them to just over 3/4 inch SL then start trading them in at local fish stores.

The only ones I cull are the deformed and runts.

[Yellowtail]

Have decided to move the fry to bigger aquarium as I was doing 50% water change every day and I noticed that the sand was turning black and the water had a foal smell to it. Moved them 3 days ago in tank with mutch finer layer of sand. Lost about 13 fry over the 3 days.

I just hope I have not move them to soon as I am worried thy might not find food as easy in bigger tank. Counted 134 fry tonight still seems to be doing fine.

Started adding half a quality crashed Tetra catfish tab tonight.

[VelcroWY]

I used to breed and raise a great number of corys and I used 10g tanks to raise the fry - usually about 100 per tank. I did 50% or so water changes every day. I found very low loses and fed microworms & newly hatched brine. I had very shallow sand, less than 1/4". After 3-4 weeks, I'd split about half off into another tank. 50-75 fry in a 10 gallon was usually my upper limit and I could keep them in there until sale date. I used a sponge filter initially and then added a second sponge filter after about a week. The sponge filters had rather mild air flow.

[Yellowtail]

Bronze Corydoras now 8 weeks old. 91 off the original 160 sirvived. Not quite happy with that. Lost most of fry that died within 5 days after I moved them to a bigger aquarium.

Well the serviver are all selebill size and off to LPS over the weekend. I have cept 18 back to stock to of my show aquariums.