Corydoras adolfoi surprise eggs

[-carlo]

I've been feeding lots and high quality foods to get my 4 adolfoi in breeding condition and apparently it worked!

Today I siphoned the sand to remove my l121 poop and while emptying buckets in the sink i found 2 eggs between the poop.

They have laid eggs before but usually on plants or glass, didn't know they also laid on the sand.

Any advice on getting them to hatch and raising the fry?

Currently I have them in an external breeder box with a connection to the main tank. So the water gets changed constantly. I've put in a small ramshorn snail to clean the eggs to prevent fungus. And also covered the breeder box to keep it dark.

[-carlo]

Today I found 9 more bringing the total to 11. So far no fungused ones. Hopefully they hatch, because that would be a first for me. If they do I plan to feed 'filter sponge grunge' (for the micro-organisms), baby artemia, crushed food, and repashy. Sadly I don't have microworms, but I think this should be okay.

[-carlo]

I don't get it. Today there are only four eggs left. Somehow the live eggs get fuzzy with a thin layer of fungus and I guess the snails eat them. What could be the cause of this?
My guess is either tiny particles in the water (main filter broke, had to install internal filters) or too little water flow. The water in the breeder box keeps moving and taking new water from the main tank, but the eggs are not bouncing around or anything.
Thing is, I have used an egg tumbler before and eventually those eggs fungused too.

I have had serveral spawns with them but have not been able to get them to hatch. Will methylene blue help me?

[-carlo]

Yesterday got another 10 eggs. This time put them in the egg tumbler.
Now, a day later, these eggs are covered in fungus as well.

Is it possible my fish are just too old? I got them from a breeder who stopped breeding them. He said they were wild caught so they probably close to 5 years or older.

I think I will try just one more time. I ordered some methylene blue (which is hard to get here) in powder form 5gram.
Anyone know how to dose this?

[Piotr]

I use Tropical Healthosan. I give to water with corydoras eggs a few drops. This is important how many L has your tumbler.

[-carlo]

Piotr it is a ZET-55 Ziss Egg Tumbler, speed is adjustable but I set it so the eggs constantly move.

[Piotr]

Before spawn I prepare a little aquarium ca. 15 l with leaf of ketapang (Terminalia catappa)and four cones of black alder (Alnus glutinosa). I have 5-8 such aquariums before spawn. Water prepare throught 3-4 weeks. And I didn't have problems with harmful factors. Sometimes, where many Corydoras spawning and I haven't aquariums get to water (15l) 4-5 drops Tropical Healthosan. If you have any question yet write please. I can make film with prepared aquariums.

[-carlo]

Thanks Piotr, I will try that if this attempt doesn't work. I don't have another tank for that at the moment.

This time I found 14 eggs, I separated them into two small plastic cups which float in the main aquarium. The cup is filled with a layer of 2 cm water. One cup I treated with methylene blue, the other I poured some homemade catappa extract in so the water is tea colored. In the catappa cup I also put some small ramshorn snails (got the idea from the thread 'Live tips to save cory eggs')

I'll try to snap some pics of the eggs as I get home since I have trouble telling which ones are fertilized.

As you may have noticed I am trying everything to hatch these eggs. Any more suggestions would be appreciated!

[TwoTankAmin]

There is another potential explanation here. The eggs are not fertile for some reason. This results in fungus and no fry.

If you go the methyl blue route, be sure to remove it from the water when you see wigglers. That is what I was taught to do many years ago. I would hope directions for dosing would come with it, if not see if the manufacturer has a web site with the information. Here I get it in liquid form never seen powder.

I used to have a few small rocks covered with java moss in my planted tanks which I would move into a cory hatching tank to provide infusoria for the newly free swimmers. This was enough to get me to where the Hikari frozen BBS could be fed. (Many folks will hatch their own live BBS.) If you have lots of eggs, you may need to culture your own infusoria, directions for this are all over the net.

[-carlo]

https://imgur.com/a/oTAJYGy

I hope this is working. Some pics of the cups with eggs. I'm not sure they are fertile TwoTankAmin, can you tell?

I sure do hope so, I have a total of 30 now.

[-carlo]

Day 2. All the eggs seem good. I've never had these eggs hatch before so I'm uncertain if they are fertile.

New pictures: https://imgur.com/a/EWBDf99

The weird-looking ones I found in the sand so the sand sticks to the egg.

[-carlo]

A little update,

3 days later none have hatched. This is likely a fertility problem. The eggs in methylene blue have all fungused. However the eggs in catappa extract water are with an exception of two all still good. This is amazing because I think none of the eggs were fertile.

I have 3 females and one I suspect is a male but maybe too old to reproduce(?). Do you think getting new adult males for this group makes a difference? Or is it something related to the lack of barbels they all have?

[Piotr]

I think - two youngest males you need to this group. When you have eggs and with all is the same problem - i think you need others males.

[-carlo]

As a conclusion to this thread, the male was not fertile. I added 10 more "adolfoi" (which turned out to be duplicareus) and they are spawning as well. I have 1 female adolfoi still laying eggs but these all develop fungus every time. The duplicareus eggs do hatch.

I'm also quite certain these species do not interbreed. The female adolfoi is not interested in the duplicareus males. So for anyone scared of hybridization, that chance is very very small.

[Mexnotex]

Hello, sorry I just look at your thread.
Eggs are infertile for sure and males probably too young, but the females are full of raw and get the urged. All I can recommend is patience as the young males will catch up.
I looked at the pictures but cannot really see the eggs. Next time take a really close up pictures.
Also, once young age the eggs in your container and add one drop of methylene blue, you need to do water changes every day at least 50%, so by the end of the 4th day you have no blue what so ever, and it is when corydoras eggs star to hatch.
Best regards,
M. Ortiz

[Piotr]

@-carlo
eggs from Corydoras duplicareus are much bigger than Corydoras adolfoi. Both species spawn in my aquariums.