Live tips to save cory eggs

[francoisMtl]

It is actually a two subjects question post. Should it be split in two?

2-3 years ago, I got Corydoras aeneus (Bronze Cory), who spawn. I took out the eggs and hatch them in small container with methylene blue. Everything was fine and got a fairly high hatching rate, only the unfertile eggs were not hatching!
Last year, I got few spawns of Corydoras CW010 (orange laser). I took out the eggs and add methylene blue. Very few did hatch and out of the few, most if not all died soon after hatching. I change the dose, I switch from Methylene blue to Acriflavin at different doses but the rate was still very poor. It was not a male fertility problem as unfertilized eggs turn white within 24 hours.

I have seen reading this forum, other Cory (C.rabauti) might be sensitive to Methylene blue to some degree (some are using small dose of blue and only once).

A- Did you experience such sensitivities with your fish and what were they?

Finally, I decided to put the eggs with every organism thriving in my tank which eat algae and or fungus.
The eggs were put in the presence of the red Ramshorn snail, Gammarus (do not the exact species), Methylene blue, or acriflavin.
The containers with red Ramshorn snail or Gammarus gave over 90% hatching rate, the two dyes gave less than 10% and the fries were less motile and died soon after. Red Ramshorn and Gammarus do not harm the eggs (egg count is the same all other the 4-5 days incubation time), they jump on the eggs and possibly clean them during after few hours, they then left the eggs safe.

B- Have you ever tried something else than chemical agents to save eggs? Like these snails or shrimps?

Right now, corydoras panda and Aspidoras albater are both reproducing and eggs are going directly with red ramshorn snail and everything looks fine.

[Narwhal72]

I have orange shrimp and ramshorn snails in most of my cory breeding tanks and haven't had any problems.

Assassin snails on the other hand are egg murderers and any tank that has them will lose eggs.

I also add alder cones to my tanks with cory eggs. This does a great job at reducing fungal growth.

Andy

[pleconut]

Do either of you have Indian almond leaves some people keep them with shrimp, these also do have a natural antibacterial effect -but do release tannins - so could also be helping the eggs/fry, but as mentioned by Andy some snails would eat eggs. If what you're doing is working and it sounds like it Is- best to stick with it.

[Narwhal72]

I also use Indian almond leaves. But more often with cichlids than with cory's or plecos. They turn the water too dark for my taste.

[francoisMtl]

Alder cone and almond leaves will slow down bacterial and fungus growth.
Snail like the Red Ramshorn will eat the fungus and then clean up the eggs.

Planorbus cleaning eggs

CorPlan734.JPG (90.57 KiB) Viewed 16505 times

Planorbus cleaning eggs (blow-up a little blurry)

CorPlan737.JPG (75.52 KiB) Viewed 16505 times

Eggs with Planorbus in left container and eggs with gammarus in right container

This last picture was taken right after the eggs where put in the container, gammarus are faster to jump on eggs, ramshorn snail will go on the eggs too. The magnification is not very good, sorry.

[pleconut]

I got some almond leaves also for my panaquolus L397s tank moreso as a trial, as i heard they will eat them. But i've been pouring boiling hot water on them each day for two weeks now and it still goes really dark, so don't think i will bother ending up using them. Probably try sourcing some other leaves safe to use maybe that won't turn water so dark.

[pleconut]

But good tips for cory breeders.

[bekateen]

Do all Planorbus clean eggs? I've got a bunch of these snails in a tank with albino corys, and it was always my impression that the snails ate the eggs (because one moment, I'd see the snails on the eggs, and later the eggs were gone). I wasn't sure it was the snails eating the eggs because the parents were still in the tank and I know they'll eat their own eggs, but I thought the snails were eating the eggs too.

If the snails are safe (and from what you're saying, beneficial), then I won't worry so much about them.

Cheers, Eric

[Erik82]

I should try thjis at home
Only problem here is that most of my fish swimms at pH 5 and dH0... the shell will fall down at these conditions...

[Narwhal72]

Pleconut- The darkness that comes out of the almond leaves is what provides the therapeutic effects. If you are leeching out the organics from the leaves before you add them then you might as well put in plastic plants as you are losing all the benefit.

[pleconut]

Thanks for the tip i do have some I've not soaked at all yet so will use these if beneficial.

[francoisMtl]

I should try thjis at home
Only problem here is that most of my fish swimms at pH 5 and dH0... the shell will fall down at these conditions...

For sure, if you dissolve the helpers before they act, then there is no hope for help... The snails will have to survive long enough to do their job of cleaning the eggs!

Do all Planorbus clean eggs? I've got a bunch of these snails in a tank with albino corys, and it was always my impression that the snails ate the eggs (because one moment, I'd see the snails on the eggs, and later the eggs were gone). I wasn't sure it was the snails eating the eggs because the parents were still in the tank and I know they'll eat their own eggs, but I thought the snails were eating the eggs too.

If the snails are safe (and from what you're saying, beneficial), then I won't worry so much about them.

Cheers, Eric

Hi Eric,
Yes, I was afraid of seeing the eggs eaten too, but at my place the eggs were all dying in blue, so I tried to incubate them with planorbus and it worked. Actually on the previous picture I counted the eggs at the beginning and the end and no one disappeared.
I found it very efficient, I presented it in fish clubs here, but no one could tell me if it was that common to use live cleaner team to save the eggs.
In fact, it is so efficient that you can keep fertilized and non fertilized eggs with the snail in the same container, even some plants will not affect the development of eggs. Snails will clean everyone and none will fungus. As you can see here, there are still some unfertilized eggs that I kept in the container for a test. They stayed 4-5 days the time the good ones hatch, you can see the newly hatched one on the picture.

So from now on, I just do daily water change with aged water and do not even worry to much about removing unfertilized eggs.
Francois

[bekateen]

Thanks Francois! I've got too many of these snails in my bigger tanks already, and I hate them there (they tend to gather on the raw veggies I feed my plecos, so densely that the plecos don't try to eat the food!). Now I have an excuse to move them into my hatchery tank.

Cheers, Eric

[Karsten S.]

Hi,

to my experience all kind of snails do eat eggs as long as they are able to.

Freshly laid cory eggs will be eaten by any snail. But as the eggs harden rather fast most of the snails are no longer able to eat them. In the hatching container I usually also put a few small snails (melania sp.) and a little bit of alder cone extract (not too much). I never used any chemicals and never have problems with fungus.

However, with (softer) eggs of other catfish (e.g. Parotocinclus) I made bad experience with the same snails.

Cheers,

[francoisMtl]

Hello,
Yes it was a surprise to me too. In fact I tested planorbus and melanoides. I also have assassin snail and Asolene spixi, but I do not feel like testing those two known carnivores (planaria for the first one and Hydra for the second).
Eventually, and after a while, unfertilized eggs will disappear whether it is because they disintegrate or because they get eroded and eaten by the snails...
Here, melanoides snails were at best neutral on cory eggs, I tried 8 melanoides (1/2” / 1.2cm long) on 8 eggs. They never really came on the eggs like planorbus will do. I witness once, one melanoide on an egg but could not tell if it was because the egg was on his way to somewhere else or because it was doing his cleaning job.
I do not say it will work on every eggs with every snails, but so far I tested planorbus with success on Corydoras CW010 (all the pictures above), Corydoras panda, Aspidoras albater, Rivulus cylindraceus al castro (a killie fish). I also have tested gammarus 3 times on orange laser cory eggs and got 2 times the feeling that eggs with gammarus were hatching something like half a day earlier, but I did not really repeat it and document it. Are gammarus harder on the egg shell? I could not say. I also once put some eggs in a small box with cherry shrimps. They did not harm the eggs as they all hatch, but I can not say those shrimps clean the eggs from dirt as there was planorbus with them.
I am no longer using gammarus but only planorbus. I found those snails are easier to handle when it come the time to pour off the water for daily water change (gammarus tend to go away with the old water...). Freshness of eggs was not tested. Although, once I took out eggs while the parents corydoras were still going around crazy. The eggs were still sticky they were attaching to the small plastic container wall (and one egg “attached” to snail shell), that all I could say about their freshness. I did not notice any decrease ratio or disappearance of eggs, again it was done with planorbus.
Planorbus are good alternative to chemical agents like Methylene blue and acriflavin as those one were clearly detrimental to some eggs development/hatching. Maybe we will come with a table of fish species and snail that could go together for higher hatching rate. Clearly it goes against general belief, that why it might be useful to share it with you guys.
Francois

[francoisMtl]

Hi,
to my experience all kind of snails do eat eggs as long as they are able to.
Freshly laid cory eggs will be eaten by any snail. ......

Actually, I suppose, I got the same kind of belief. The very first time, I tried those Ramshorn snails, I saw them going straight on to the eggs. I could not see the eggs being eaten by these pests, so I left home for a few hours (and for work eventually). When I went back, I counted the same number of eggs as I put on first and the snail was going around quietly. I suppose they had done their cleaning job and there was nothing else to eat on the egg shells.
Here is another picture of 101 young Corydoras CW010 during an aquarium transfer, all saved with planorbus (there are few consecutive spawns).

francois

[bekateen]

Those snails look pretty small. How large so you permit the snails to be? Is it that large adults will eat the eggs but small snails are unable to do so?

[pleconut]

I thought that myself. My questions were that maybe using younger and smaller snails rather than the full grown adults that would pose less of a risk? But considering that as the cory eggs are hard anyway . Another question i have could this also possibly work with large sized eggs of other fish?

[francoisMtl]

Both of you are asking if size matters...
Well, I tried to put around 1 snail per 5 eggs, not baby snail, but still not fully grown.
I may try in parallel with larger ones at the next spawn, although I do not know when the next spawn will be.
For the eggs I have tried 2 cory, 1 apsidoras, and 1 killie. I just ask on the phone one club member to try snail on some Mbuna or other rift lake cichlids eggs. Those eggs are fairly large and non adhesive.
I do not have any loricariidae spawning. You will have to try it and tell us if that works. I have very limited aquarium space so some people will have to try on their fishes and tell us if that works for them too.

[francoisMtl]

Ok guys, I have isolated 5 larges planorbus, they join the other smaller ones in one hatching pot.
What else would you like to be tested?
Eggs will come from Cory CW010 or Cory panda, they are the only two species spawning on regular time here. The other species, are too young, I got them mostly this year through local fish stores exchange with laser orange from last winter/spring. Beside few bags to club auctions, I do not sell my fish online just do exchange with LFS. This is a hobby as so cannot be a source of revenue, in addition it helps LFS and they need it. It seems tropical fish keeping is slowing down here too, but that's another topic.
I do not think testing large snails will help much. It is like having a medicine posology and trying 10 times the dose just to see if we will be sick of it! Nevertheless, I am intrigued by the answer and I will test it on few eggs. At worst, we will know to not overdose snail on our eggs.
There are few posts on this forum with concerns of fertile eggs not hatching, the best way to know if that way of doing is valid, is to test it at your place with difficult eggs. It could be a good alternative to improve hatching rate of our fishes and an alternative to chemical products use.
Here it has works on Aspidoras at another club member's place, actually it helped him to get better hatching rate. I have is breeding group now in my tank, as soon as I have at least 10 fries of 30 days old this breeding group will go to another member's tank for the club breeding award. Another club member told me it has worked on some of his killies eggs, but he did not specify which species he was breeding. This techniques seems to work here, it is up to you to try it.!
Cheers,
francois

[MChambers]

Found some CW010 eggs last night and will move them into a hatching container tonight, with a small ramshorn! Probably will also put in an alder cone, just for good measure.

[francoisMtl]

Here is a protocol:

Hatching container is ~4.5” or ~11cm diameter and ~3” or ~7.8cm tall
Isolate between 3-10 small to medium sized red ramshorn snails (Planorbus sp.)
Scrap-off the eggs and put them into small hatching container
Change water with aged water (same used for water change into the main tank)
Make water level to ~1.5” or ~4cm
Each evening, pour off as much water as you can do and replace with aged water

No air line used, the hatching rate is total for those eggs that are fertile (that do not turn white after 24 hours). So air line is dispensable with this set-up. Do not hesitate is you have question, I will be very happy to answer them.
Good luck and thank you for trying and telling us what you think.
Cheers,
francois

[MChambers]

Thanks for the advice! I'm going to be away for a few days, and won't be able to change the water, so I think I'll add an airstone. I like the idea of only 1.5" of water, though.

[francoisMtl]

I usually do not put more than 60 to 80 eggs per one container. I believe I have three females spawning: one gives 30-35 eggs each month and the other two gives a total of 60-80 eggs 15 days after the first one. It is like a clock inside the tank.
It will be interesting if you could count the eggs and split your spawn into two containers, one with some snails and one without. So you will see and possibly give us number of what was the best or if there was differences in your hatching rate.

[MChambers]

Yes, I'd like to try that, but I can't do it this time, since I'm struggling to pack for my trip and take care of many non-aquarium things.

[francoisMtl]

Some update to figure out if size matters:
on Dec. 15th, 5 large snails were isolated into small container.
on Dec. 16th, 15 Corydoras panda eggs (possibly fertile) + 1 white egg of the same batch from the morning were put within the container.
on Dec. 17th, took a picture, can still count 15 brownish eggs + 1 whitish.

They do not seem very eager to swallow the eggs.... Lets see in few days when eggs will hatch if snails do not change their mind in between and decide raw eggs are yummy!
Right now large snails produce large poops, so it is not really an advantage compare to smaller ones. Smaller ones do poop too but their waste is easily removed during daily water change.

Just for fun two additional pictures taken earlier this fall, with Corydoras CW010 eggs:

I would not go with more eggs per container, better to have two containers (still scare that embryo will consume all oxygen for their development).

It is now up to you to try planorbus, in case you have eggs difficult to hatch.
Cheers,
francois

[francoisMtl]

Some update, yesterday night at water change there was still the same number of eggs. Beside the fact these 5 large snails were staving for 3 days, they had no taste for raw eggs.
Cheers,
francois

[francoisMtl]

Another update:
Still 13 eggs, 2 have turn white the rest is still brown, and 1 fry. Missing 1 eggs to make it 15 the starting number. I could not say if it turns white and went out with water change (white eggs tends to go easier out than snail poop), or if it was injured when taken of from the spawning tank and if it somehow dissolved. Eggs are difficult to see among snail dejections... I will not recommand to go with large planorbus, they are too messy, but rather with small ones.

It is not the espected hecatomb.

I will present that finding again at two fish clubs (Montreal english Aquarium Society : MAS) and Ottawa Valley Aquarium Society : OVAS), so it will be nice to know if it is a rediscovery or something really unespected although we can not exclude that some snails species have unique diet and will never touch eggs even under starvation condition. So far, it seems to go against the general belief like Kamas88 mention it "snails eat eggs", even if he still add some small melania sp (melanoides?) in the hatching container.

Coming back to the original question:
Do you have ever heard of using live animal to take care of Cory eggs?

Thanks for your help.
francois

[MChambers]

I put some CW010 eggs in a specimen box with an airstone and several small planorbus, an oak leaf, an alder cone and some riccia last Tuesday, the 15th, and then went away for six days.

When I returned Monday, the 21st, I had several fry zipping around. (I haven't had time to count the exact number.) I don't think the yield was very good, but it wasn't any worse than I've had recently using Methylene blue. I've now moved the fry into a five gallon tank, still with an airstone.

[francoisMtl]

This is not to bad concidering you were maybe not in optimal conditions. At least it answers again the question that planorbus snail do not avidly eat eggs. Hope you will have another chance to test it with or without snail and time to count eggs along your experiment.

Here I got 10 fry yesterday and another 2 today, there is no more eggs to hatch in the container, fries have been moved to another larger container for growing with air line and food at will for 15 days or so, before they will go in 5 or 10 gallons aquarium.

Cheers,
francois