C. sterbai spawning

Post by **Marc van Arc** » 05 Nov 2006, 09:51

After months of being hardly noticed, my C. sterbai seem to have benefitted from a new and much larger tank. Lots of "fresh" water, new roots, very fine sand and spawning dithers (Danio rerio) did the trick. Eggs are scattered all over the windows and plants. Best part: they start to look like dark Corys with lighter spots instead of the other way round.

apistomaster · Post by **apistomaster** » 05 Nov 2006, 13:33

Hi Marc,
Congratulations. I don't know if others have had this experience but I have found that my Corydoras sterbai begin spawning about the beginning of October and continue through April then they shut down. I don't know if it is a truly spawning season or whether it's because m room temperatures get too high for them to breed in the summer.
All I know for sure is that Ican move my dozen breeders to a fresh tank every 4TH day until I run out of tanks and by then , after consolidating some of the fry, I can move the breeders into the new spaces and they continue to spawn. I have about 500 fry from just the past 5 weeks. I plan on going on until I reach 1000. I also notice they have a period at about one month old where the fry become very delicate. It may take anther month of further development before they become more hardy again; reminiscent to the stage anabantids go through as they tranfer more function to their developing labyrinth organ. This is when I take whatever losses I'm going to have.
To make matters worse, I am having some major hydra blooms associated with the frequent bbs feedings. I'm trying to get them used to prepared foods to starve the hydra out but the Corys do grow much faster on live foods.

Gogool · Post by **Gogool** » 06 Nov 2006, 11:28

Congratulations Marc!

I have been trying to spawn them for over 6 month now, with no luck. (I have 14 in 60ltr)
It must be quite hard to trigger the spawning process. Good luck.

Gul

Post by **Marc van Arc** » 06 Nov 2006, 12:05

Gogool wrote:I have been trying to spawn them for over 6 month now, with no luck (I have 14 in 60ltr).
It must be quite hard to trigger the spawning process.

Well, it isn't (see also Larry's post). It's the time for South-American fish to spawn. What you could try is a waterchange and make the "fresh" water somewhat cooler to imitate rain. Hope it works.

apistomaster · Post by **apistomaster** » 06 Nov 2006, 15:30

Have you ever tried changing at least 50% water changes worms everyday using cool replacent water? After about a week or ten days of this make a water change of 50% but this time use straight reverse osmosis water. Contimue the water changes but now use a 50/50 mix of RO and tap water.
During this period feed the Corydoras all the live blackworms, whiteworms or grindal worms they can eat.
Also provide a briskly bubbling airstone and use a power filter with an inlet covered wiith a sponge.
Based on our local experiences, Corydoras sterbai will spawn easily beginning in October and continuing throught the end of April.
I have not encountered this seasonality with the aquarium strains of C. aeneus reg or albino and Corydoras paleatus.
The sticky topics and the breeding Corydoras sterbai article contained in Shane's world should provide you with as much information you need. Of course it is always necessary to have mature fish and both sexes. Obvious as this is it is a good idea to make sure. Two males to each female is a good ratio and they are most easily spawned in groups of 6 to 12 fish.

Gogool · Post by **Gogool** » 07 Nov 2006, 11:39

Hi,

Thank you for your tips apistomaster. I will follow that water change regimen.
I will post results.

Thank you,
Gul