i've got eggs! now, i've got questions too...

Bathos · Post by **Bathos** » 23 Feb 2003, 17:16

this is my first spawn of Corydoras aenus. i'm very excited, as this is the first fish mating i've observed. it's so cool! now, i have a few questions though...

1) how do i know when they're done mating?
2) what should i feed the fry, and when? i have some fry food for egglayers and was going to start with that, as i've failed miserably at culturing infusoria. would plankton also be a good dietary supplement? when will they be ready for brine shrimp and grindal worms?
3) they're in a 20gal long with a whisper 2 power filter. i'm afraid they'll get sucked up into it. even when i have the filter on low the current is fairly strong. what should i do about this? will putting a sponge over the intake help?

thanks so much for your help. i really want to do this right this time!

-Liz

Bathos · Post by **Bathos** » 23 Feb 2003, 22:19

well, they started around 10:00AM, it's now about 5:20PM and they're still spawning. how long will this last? a few more hours? days? i've been checking books and web resources, but none seem to mention this. how long do your cories usually spawn?
-Liz

Post by **Coryman** » 23 Feb 2003, 22:20

Bathos

First signs the mating is all finished is that the female ignores the males advances.

If your C aeneus are in a comunity tank then the best advice would be to remove the eggs, they are quite tough and handleable, use a razor blade to remove those on the glass. float a small container in the main tank containing the same water, put the eggs in the container and add an air stine to keep the water moving. This helps stop particles from settling on the eggs an causing problems. It takes four days for the eggs to hatch and another two for the fry to abrorb the yoke sack. C. aeneus fry are large enough to take hewly hatched Brine shrimp but it should be suplimented with finely powdered flake pre-soaked to make sure it goes straight to the bottom. Change at least 50% of the water in the container daily using waterfrom the main tank. The fry should be large enough in 6 to 8 weeks to introduce into the main tank.

Ian

Bathos · Post by **Bathos** » 23 Feb 2003, 22:30

i had just finished fishless cycling a 45gal tank, so all other former inhabinants of the 20gal are now in the 45gal. (talk about a lucky break!) i don't have a razor blade, so i can't remove the eggs, but i'm ok with that. i was going to move the parents to the 45gal as well, once they were finished. is that a good idea? if the current from the filter will be too strong for the fry, i can always just put the filter on another tank until the fry are older. would the nitrifying bacteria on the gravel would be enough to support the fry at the beginning? thanks so much for your help!
-Liz
PS i'll start the brine shrimp culture once they hatch. i had no idea they'd be big enough for the baby brine shrimp right out of the egg!

Post by **Coryman** » 23 Feb 2003, 22:40

Taking the adults away is a good idea, they may leave the eggs alown but why take that chance.

Can you put a piece of sponge over the filter intake, this will stop any fry from being sucked in. When feeding though I would turn the filter of as it will draw the food to it. The other alternative would be to use a large air driven sponge filter, they work very well with fry and after a short time there will be a residue on the sponge that the fry will graze on.

Ian

Bathos · Post by **Bathos** » 24 Feb 2003, 00:24

i'll deffinately put a sponge over the filter intake. i'd love to use a sponge filter, but we have a dirth of decent sponge filters in the area. i had been looking at them online for a few weeks, but i don't think they'd get here in time. (i was thinking of getting the stackable kind of sponge filter so there would be more surface area for growing things (infusoria/bacteria), but i hadn't ordered them yet) how powerful should the air pump be? i only have a few small ones at the moment.

will it be a matter of days or a matter of hours before the cories are finished? last i checked, they're still spawning...

-Liz

Post by **Rusty** » 24 Feb 2003, 01:00

Bathos, are you anywhere near Lancaster, PA? That Fish Place's showroom and warehouse are located there, and they probably have one of the best selections around.

Rusty

Bathos · Post by **Bathos** » 24 Feb 2003, 03:17

That Fish Place is kinda far actually. i'm near Philly, so it's at least an hour away, maybe more. i don't know if i can get there soon. mondays i stay late at work, and we're supposed to get snow. tuesday i'm supposed to go somewhere after work. might be calling it close with the hatching time. do you think they'd be all right if they hatched in a tank with just some air stones and no filter? i could take the filter out and put the air stones in on wednesday before i left...
-Liz

Post by **Coryman** » 24 Feb 2003, 22:02

Can you raise the filter so that it is 2 or 3 inches from the substrate.

I think a piece of sponge over the filter intake is still favourite, keep it in place with elastic bands.

Ian

Bathos · Post by **Bathos** » 25 Feb 2003, 02:04

i could certianly lower the filter intake. right now it's between 4 and 4.5 inches above the substrate. why does having it at that height help? is it because it's further from the bottom, where the fry would initially be after hatching? also, will regular rubber bands work, or do i need a special kind of rubber band? thanks so much for the help. i don't want to mess this up and kill my fry!
-Liz

Post by **Coryman** » 25 Feb 2003, 19:30

Bathos

I should have said 2-3 inches as a minimum, higher than that is OK. Any regular rubber bands will be OK, by the time they start to perish the fry should be large and strong enough to be able to avoid the filter intake.

Ian

Bathos · Post by **Bathos** » 26 Feb 2003, 21:47

thanks so much everyone! everything's all set for the arrival of the fry. hopefully this will be a good batch and i'll be able to care for them propperly this time.
-Liz

Bathos · Post by **Bathos** » 28 Feb 2003, 13:45

about half of the non-fungused eggs hatched yesterday. the fry are translucent except for a small trinangle on top of their tiny heads, which is a dark green-grey, and their eyes, which are pretty big for such a small fish. they aren't much bigger than the planaria themselves.

there are some eggs that i was looking at last night and saw the tiny fish turn around in once, then stop moving. some of the fry-filled eggs have not hatched yet. will they? did they just die in the egg? is the shell too thick for them to get out? what are your experiences with this?
-Liz