Limited success (Corydoras eversi)

[finzz]

These catfish have been making me crazy for the last couple months. I've had 8 spawns for a total of over 200 eggs and I have 3 one-day-old fry. I did have two eggs hatch on an earlier spawn but they never really swam; just circled for a while and then stopped. These three look pretty good so far. I may finally be getting the water right, but certainly not right enough yet!

 

[zendog]

Congratulations! Good luck with the little fellers and please share how they do.

Mine finally spawned for the first time (at least that I've noticed) with the storm that went through yesterday, but by the time I pulled eggs today at least half were going white so who knows how the rest will do. I have about 15 eggs left that look like they might be viable. They're in a small tub with alder cones, rams horns and an air stone. Based on expected survival rates I guess I'll get about 0.225 fry. I'm about half tap and half rain right now so I'm not hopeful.

They had hidden the eggs behind the sponge filter, so I probably wouldn't have noticed except I happened to see two eggs stuck to the top of rams horn snail roaming the tank.

 

[finzz]

Thanks, and good luck to you as well! I'll make you a deal: if you figure them out, let me know, and I'll do the same for you if I figure them out. They are a puzzle (at least for me).

 

[mchambers]

Good luck to both of you!

 

[finzz]

Congratulations! Good luck with the little fellers and please share how they do.

Mine finally spawned for the first time (at least that I've noticed) with the storm that went through yesterday, but by the time I pulled eggs today at least half were going white so who knows how the rest will do. I have about 15 eggs left that look like they might be viable. They're in a small tub with alder cones, rams horns and an air stone. Based on expected survival rates I guess I'll get about 0.225 fry. I'm about half tap and half rain right now so I'm not hopeful.

They had hidden the eggs behind the sponge filter, so I probably wouldn't have noticed except I happened to see two eggs stuck to the top of rams horn snail roaming the tank.

Hey, Walter;
How did the eggs do? Hope they fared well and you've got young C eversi swimming around now. Let us know!

I think I may have figured something out about these fish (finally).

 

[zendog]

Hi Don,
No joy with the eggs for me. After about going white pretty early on, the alder cones and rams horns seemed to keep most of the others okay, but they just sort of went opaque after the second day or so.

They've actually layed a few more I can see on some java moss stuck on the intake of my filter, so I'm keeping an eye on those. It is just a few, but at least a couple still seem like they might be viable, although I expect it is water conditions and these will just go opaque as well.

What do you think the secret is? I was thinking of going with all rain and then a whole bunch of oak leaves to push it more acidic and stain the water. I'll probably miss the eggs with that thought, so I'd have to hope for the spontaneous survival in the tank.

 

[finzz]

I'm sorry; I thought maybe your methods would create an environment that would be more suitable for the eggs to hatch out than mine do (then you could tell me!).

What I'm in the process of trying right now seems to be working at least better than previous attempts and we may be thinking along the same lines already. I had decided to change over all the water to soft/acidic without adding any artificial buffers for acidity, thinking that maybe the additives were causing poor fertilization of the eggs I drained the tank down to about a half an inch of water and filled with rain water, some of it coming from the blackwater tank outside. With the tank that empty and the Corys going nuts, I noticed there were 4 or 5 fry shooting around the bottom of the tank. I'm almost positive that I removed a far greater percentage of eggs than I left in the tank during all the previous spawns, so I assume they hatch much better where the adults placed them than in my containers and small tanks.

Right now I have yarn mops covering 3/4 or so of the tank floor and when I hooked one this morning and raised it up, 10 or 12 fry, probably a day or two old, swam for cover under the next mop. I'll let you know what happens from here. pH now is at about 5.8 or 6.0 and TDS is next to nothing.