Live tips to save cory eggs

[bekateen]

My closing observations on the trilineatus eggs: This morning, five eggs remain unhatched but appear viable. Fifty two fry are in the container; four of these are dead.

Okay, one more trial, just for fun. This time, fresh oil cat Centromochlus perugiae eggs (68 of them) which were laid overnight. The setup is exactly the same as last time - 1 cm deep water, no active aeration or circulation, the container floating on the water surface in parents' aquarium, daily ~75% water changes taken from parent tank, with three medium sized Ramshorn snails. Let's see how this ends.

To clarify the photos, the plants you see in the photos are not IN the egg container, they are in the main aquarium, UNDER the egg container.

Cheers, Eric

[pleconut]

Congratulations on another spawning! Hoping the snail and egg combination works well here also. I'm hoping my ABNs will also do so soon, it's looking imminent, but then it has been for some time now.

[bekateen]

Alas, this test with the oil cat eggs is already a failure. Within an hour of moving the eggs to the container, the eggs started lysing (bursting open); I actually saw one burst with my own eyes.

This type of response, in my mind, makes me suspect that there was an osmotic problem with the eggs in the water. However I can't see how this could be the case, since the egg container water was taken out of the same tank in which the eggs were laid. The other possibility I can imagine is that these eggs were so fresh that they were extremely fragile and hadn't hardened up yet (which I know happens to cory eggs, but I don't know if this also occurs to oil cat eggs). Maybe I should have left these eggs with their mom in her cave for another day before transferring them to the incubation container.

Within a few minutes of this picture being taken, the number of apparently "intact" eggs had dropped from the 68 of my original count to less than 20! And in case anyone is wondering, I saw no evidence that the snails had anything to do with the eggs bursting. The one egg I saw burst was nowhere close to any of the three ramshorn snails.

Dang!

[pleconut]

Not sure if there's a time after which the eggs harden, as I've no experience with centromochlus perugiae whatsoever to know. Could the large diference in water volume ie the tank and container been a factor, and do either of the parents care for the eggs in anyway, I might seem a bit naive, but just some thoughts.

[bekateen]

Water volume shouldn't matter, but a change in the relative water tonicity would matter. Tonicity = a relative measure of the water diffusion force created between two water solutions separated by a membrane - in this case, the water in the container compared to the water inside the eggs; when there is an imbalance in the tonicities between two solutions, water will spontaneously move across the membrane, either INTO the cells causing the cells to swell and lyse (as seen in my cells) or OUT OF the cell causing the cells to shrivel. Obviously, neither of those actions is good for eggs. Tonicity is imperfectly linked to the relative osmolarities (concentrations of all solutes, salts, proteins, whatever, in the water). Although not universally true, water solutions with more ions and other substances dissolved in them (i.e., higher TDS) will be hypertonic compared to water solutions with fewer solutes (i.e., lower TDS), and these higher TDS solutions will leach water out of the lower TDS solutions.

Since the eggs were laid in the tank last night, the eggs were deposited into a certain quality of water with a particular TDS (which I didn't get a chance to measure this morning). I took water out of that tank to fill the egg container, so the osmolarity should be identical, and thus the relative tonicity should be unchanged - I.e., if the eggs didn't lyse in the aquarium, they shouldn't lyse in the container either.

There is some parental care performed by female oil cats: The eggs are laid on the walls of a cave (like many plecos) and the MOTHER (not the father, as is the case for most plecos) stays with the eggs and guards them. However, I don't know how much active care of the eggs occurs: When I watch my mothers with their eggs, I never see any strong "fanning" activity by the moms; if anything they seem disinterested in the eggs, but they do stay with them. So maybe there is some fanning, but I haven't observed that personally.

Cheers, Eric

[pleconut]

Thank you for the clarification. Hoping you see another spawning very soon.

[MChambers]

Would adding methylene blue change the tonicity?

[bekateen]

Would adding methylene blue change the tonicity?

Good question. Anything soluble in water, but which CANNOT penetrate the cell membrane, will change the tonicity. If the methylene blue is able to enter the egg cells, then it will not change the tonicity. If it is trapped outside of the egg cell, then it will change the tonicity.

To be clear, I did not add any methylene blue to my container. If the ramshorn snails are controlling (eating?) the fungus, then no medication should be necessary.

Cheers, Eric

[francoisMtl]

Hi Eric,
Sorry for your loss...
At first I wanted to ask you if you were sure these eggs were fecund. But I saw your post (http://www.planetcatfish.com/forum/view ... =7&t=42368) and that is not their first spawn... Did you notice low fertility in the firsts spawns?

Congratulation for your Corydoras trilineatus, very nice pictures and detail report.
So we can add this species to the list. Here I got success with Corydoras aeneus and right now I have some Corydoras paleatus eggs with ramshorn snails, should be able to report the output in few days.

Ancistrus sp. (Gold) False L144? francoisMtl Montreal,Qc
Aspidoras albater francoisMtl Montreal,Qc
Corydoras aeneus francoisMtl Montreal,Qc
Corydoras boesemani syno321 Edmonton Ab (PlanetCatFish)
Corydoras C123 MChambers Washington DC (PlanetCatFish)
Corydoras carlae syno321 Edmonton Ab (PlanetCatFish)
Corydoras CW010 francoisMtl Montreal,Qc
Corydoras CW010 MChambers Washington DC (PlanetCatFish)
Corydoras CW010 syno321 Edmonton Ab (PlanetCatFish)
Corydoras duplicareus MChambers Washington DC (PlanetCatFish)
Corydoras panda francoisMtl Montreal,Qc
Corydoras schultzei (venezuelanus black) francoisMtl Montreal,Qc
Corydoras sterbai francoisMtl Montreal,Qc
Corydoras trilineatus bekateen Stockton CA (PlanetCatFish)
Fundulopanchax gresensis Takwai francoisMtl Montreal,Qc

Cheers,
Francois

[francoisMtl]

Just thinking of it, would it be safer next time to split eggs in two chambers with or without snails?
I would have love to add your Centromochlus perugiae to the list. Those snails may protect more species eggs than just corys, one ancistrus and one killie.
Francois

[bekateen]

Hi Francois,

As for my previous spawns, I've had decent survival (except for my first spawning: they were over a month old when I accidentally unplugged the heater on Thanksgiving, and then forgot to plug it back in; those babies all died overnight), but the egg clutches have not been so large. Each spawn produces more eggs, and I think this spawn at 68 eggs is about my largest.

As for spitting the eggs into two batches, with and without snails, that is would be a good control experiment, but it would help if something about the water caused the cell lysis and the waters are coming from the same source. That said, I've recently been informed that baby perugiae tend to survive very well if just left with mom, so even if ramshorn snails do reduce fungusing, it may be that I'm just better off leaving them with mom.

Cheers, Eric

[francoisMtl]

One more to add to the list: here some Corydoras paleatus eggs have survived treatment with Ramshorn snail and were born healthy! They are now growing up with some C.schultzei black.

Ancistrus sp. (Gold) False L144? francoisMtl Montreal,Qc
Aspidoras albater francoisMtl Montreal,Qc
Corydoras aeneus francoisMtl Montreal,Qc
Corydoras boesemani syno321 Edmonton Ab (PlanetCatFish)
Corydoras C123 MChambers Washington DC (PlanetCatFish)
Corydoras carlae syno321 Edmonton Ab (PlanetCatFish)
Corydoras CW010 francoisMtl Montreal,Qc
Corydoras CW010 MChambers Washington DC (PlanetCatFish)
Corydoras CW010 syno321 Edmonton Ab (PlanetCatFish)
Corydoras duplicareus MChambers Washington DC (PlanetCatFish)
Corydoras paleatus francoisMtl Montreal,Qc
Corydoras panda francoisMtl Montreal,Qc
Corydoras schultzei (venezuelanus black) francoisMtl Montreal,Qc
Corydoras sterbai francoisMtl Montreal,Qc
Corydoras trilineatus bekateen Stockton CA (PlanetCatFish)
Fundulopanchax gresensis Takwai francoisMtl Montreal,Qc

Cheers,
Francois

[bekateen]

Hi Francois,
You're building a nice list of successes!
Cheers, Eric

[francoisMtl]

Hi Francois,
You're building a nice list of successes!
Cheers, Eric

Yes Eric, it seems canadian winter is good for them. Last year, CW010 were breeding each three weeks, they then stop at spring and summer time...
I am not the only one to have some success, syno321 just sent me a PM to add weitzmani and c120. The race is on! Which cory is next? Reading your post (What do ambiacus fry look like?), should we add your C.aeneus and C.ambiacus to that list of success?

Ancistrus sp. (Gold) False L144? francoisMtl Montreal,Qc
Aspidoras albater francoisMtl Montreal,Qc
Corydoras aeneus francoisMtl Montreal,Qc
Corydoras boesemani syno321 Edmonton Ab (PlanetCatFish)
Corydoras C120 syno321 Edmonton Ab (PM PlanetCatFish)
Corydoras C123 MChambers Washington DC (PlanetCatFish)
Corydoras carlae syno321 Edmonton Ab (PlanetCatFish)
Corydoras CW010 francoisMtl Montreal,Qc
Corydoras CW010 MChambers Washington DC (PlanetCatFish)
Corydoras CW010 syno321 Edmonton Ab (PlanetCatFish)
Corydoras duplicareus MChambers Washington DC (PlanetCatFish)
Corydoras paleatus francoisMtl Montreal,Qc
Corydoras panda francoisMtl Montreal,Qc
Corydoras schultzei (venezuelanus black) francoisMtl Montreal,Qc
Corydoras sterbai francoisMtl Montreal,Qc
Corydoras trilineatus bekateen Stockton CA (PlanetCatFish)
Corydoras weitzmani syno321 Edmonton Ab (PM PlanetCatFish)
Fundulopanchax gresensi "Takwai" francoisMtl Montreal,Qc

Cheers,
Francois

[bekateen]

Hi Francois,

You can add my aeneus (although I see that you already have aeneus on your list), but please wait before you add ambiacus. The color pattern in these fry sure looks like they will be ambiacus, and I don't recall my trilineatus fry looking like this when so young, but I want to give them more time to mature before I definitively settle that they are ambiacus. I'm 95+% confident that they are ambiacus, but I want to make sure that some big black dot doesn't start to develop on the dorsal fin as they age (in which case they are just trilineatus).

With both my current aeneus and these suspect ambiacus juvies, I should let you know that I did not use the same incubation cups as I used in my earlier experiments. Rather, I dumped my most recent eggs directly into my 2.5 gal tank hatchery/fry tank which has a 78F heater and a sponge filter, and into which I've added a group of ramshorn snails. So these eggs did rely on the RH snails to prevent fungusing (with no additional chemical protection (no methylene blue, etc)), even though they weren't raised in the confines of the small bowls with daily water changes. I did notice a few fungused eggs in this larger container (compared to what I saw in the little cups), but the vast majority of the eggs hatched into nice fry.

As I said above, I'm almost 100% confident these are ambiacus. Besides their color pattern (the strong black color of the dorsal fin spine), there are two other items I've noticed which incline me towards this conclusion are that (1) these juvies are growing much more vigorously than my trilineatus have in the past, and (2) these juvies are really easily scared; that is also true of my ambiacus parents, but is not as true of my trilineatus (either my parents or past juvies).

Cheers, Eric

[francoisMtl]

Hi Eric,
This list is for Cory eggs that were protected from fungus through the use of Ramshorn snails. If you are convince those snails did protect eggs, then your cory should be added into that list. Obviously using small containers or cups allow to watch what is happening to each egg almost individually and for sure allow to count eggs before and after incubation time. However, it may not be the only way to get snail protection. Actually I do use aged water but no air line, you used tank water, others may feel more comfortable to add one air line, etc... So already with the use of small containers, protocols can vary. One thing which is constant: in each case so far snails protected eggs from fungus without the use of chemicals.
Yes, Corydoras aeneus is already into the list but this was done away from your place and your aeneus will be independent confirmation of the previous one. I was wondering if I should leave triplicate of CW010, but it shows robustness of this way of doing. So why not adding your Corydoras aeneus?
We will wait for the Corydoras ambiacus that you alleviate the uncertainty of their identification. Although it will be nice if they could be Scleromystax barbatus, that way it will be another genera for which Ramshorn snails are protective!
Cheers,
francois

[bekateen]

Hi Francois,
Indeed you are right. Please do add my aeneus to your list. I'll let you know about the other species as I confirm their IDs.

Cheers, Eric

[bekateen]

Hi Francois,

Without a doubt my juveniles are Scleromystax barbatus. You can add them to the list. Sadly, no ambiacus fry in the group at all.

Cheers, Eric

[francoisMtl]

Hi Francois,
Without a doubt my juveniles are Scleromystax barbatus. You can add them to the list. Sadly, no ambiacus fry in the group at all.
Cheers, Eric

Hi Eric,
With your C.aeneus and S.barbatus, this list start to be significant: 20 catfish so far, and the word is spreading outside of catfish eggs protection as Jody from Ottawa got success with his angel fish eggs and is now trying Pundamillia nyererei a mouthbrooder cichlid (I put the link below).

Ancistrus sp. (Gold) False L144? francoisMtl Montreal,Qc
Aspidoras albater francoisMtl Montreal,Qc
Corydoras aeneus francoisMtl Montreal,Qc
Corydoras aeneus bekateen Stockton CA (PlanetCatFish)
Corydoras boesemani syno321 Edmonton Ab (PlanetCatFish)
Corydoras C120 syno321 Edmonton Ab (PM PlanetCatFish)
Corydoras C123 MChambers Washington DC (PlanetCatFish)
Corydoras carlae syno321 Edmonton Ab (PlanetCatFish)
Corydoras CW010 francoisMtl Montreal,Qc
Corydoras CW010 MChambers Washington DC (PlanetCatFish)
Corydoras CW010 syno321 Edmonton Ab (PlanetCatFish)
Corydoras duplicareus MChambers Washington DC (PlanetCatFish)
Corydoras paleatus francoisMtl Montreal,Qc
Corydoras panda francoisMtl Montreal,Qc
Corydoras schultzei (venezuelanus black) francoisMtl Montreal,Qc
Corydoras sterbai francoisMtl Montreal,Qc
Corydoras trilineatus bekateen Stockton CA (PlanetCatFish)
Corydoras weitzmani syno321 Edmonton Ab (PM PlanetCatFish)
Corydoras trilineatus bekateen Stockton CA (PlanetCatFish)
Scleromystax barbatus bekateen Stockton CA (PlanetCatFish)

Non Catfish:
Fundulopanchax gresensi "Takwai" francoisMtl Montreal,Qc
Pterophyllum scalare (angel fish) Jody Ottawa On (OVAS forum)

Cheers,
Francois

[bekateen]

Hello Francois (@francoisMtl),

You can add Corydoras diphyes to your list. These were incubated like my trilineatus eggs, in a small container of water, ~1-2cm deep, no aeration, floating on surface of parents' tank, with daily pour-dip-and-refill water changes from parents' tank. Incubated for 5.5-6 days with 3-4 Ramshorn snails of different sizes, very small to pretty big. Not all eggs were fertile and not all will hatch. But the Ramshorn snails didn't eat the eggs, and no fungus developed.

Cheers, Eric