Breeding colors

[modealings]

Hi all - I have a single breeding pair right now. They lay eggs about every week. I havent made much of an effort raising any fry but I just wanted to share the difference in coloring on this male when they have a spawn. I'm new to all this but hard to believe it's the same fish!

Male w/ eggs:
99611

Male w/o eggs:
99609

Female:
99610

[Quintin]

Yes they go dark due to excess slimecoat being produced for fry.and baby discus practically blind and can see dark colour of parents

[modealings]

Thanks - now if they would only always have eggs so they are that colorful haha! (Also it seems like there should be white sponge filters so the fry arent attracted to the dark foam.)

These fry actually hatched last night. It was interesting bc I just moved cities. In my previous place, the water was very hard (>300tds per city report and it would always leave sediment deposits on my tank and equipment). But I would estimate 30-50% of the eggs were still able to hatch. The new water is still hard (265 tds) but they wouldn't hatch after 4-5 attempts. This time I waited until they laid eggs, and then over the course of the next 24 hours did wc's with RO to bring the tds down to 100ppm. I'd estimate a ~75% hatch rate this time.

I think I had read nc0gnet0 talking about how a high tds can effect the actual eggs hatching vs the fertilization process. I think this could speak to that as well. That being said, it could be a sliding scale - if the water is so hard then the eggs very rapidly become impenetrable and cant even be fertilized. If slightly less hard, they can be fertilized but wont hatch. And if appropriately soft, they will fertilize and hatch.

Anyway I just thought it was interesting. And for me a way to save money and time by not using RO until the eggs are laid.

[MD.David]

The TDS puts pressure on the egg, the higher TDs the higher the pressure. This is why you may see bigger eggs then others, (if the TDs is too low you may see the eggs swell, because the pressure "in" the egg is greater then the pressure in the tank). Each water chemistry is slightly different so you have to play with it a bit to see how it reacts with your particular water in your area.
I'm not an expert in this, but I have seen this happen in my breeding, at first I thought it was weird and maybe a fluke but I did see research and it was because of the pressure in the eggs vs the pressure in the tank. It's a lot of science that goes into a successful breeding operation.
But the TDS is only one of many factors in the hardness of the egg shell, calcium can cause more hardness as well among other factors.
This is how I have come to understand this, if someone else sees an error in my understanding i would like to see other thoughts as well.

Cheers,

[modealings]

Thanks that does make sense. So I wonder if it's more about the osmotic gradient creating this pressure or actual sediment deposits on the egg surface itself. Like you said, a high TDS creates a high osmotic gradient which can cause the egg to shrink like a raisin. A low TDS thus could cause it to balloon like a grape. Then sediment deposits separately can cause increased hardness of the shell itself. Am I thinking about this correctly?

Also so this batch hatched but the wrigglers died after 24hrs. I did transition back to tap at 270ppm after they hatched. My plan is to sanitize the tank, then PP the pair when I put them back.

[MD.David]

You are correct.
When I breed mine I short for TDS of 45ppm while breeding then about the same till hatching, then I will let it raise till about 75ppm till they attach, then I do straight tap water with ½ a cap full of discus essentials minerals (in a 20g) for a tds of 110-135ppm, this tds is my tap water so it will be like this for the entire grow out.
I've dropped the TDS down to 20 ppm before this is when I noticed the eggs enlarged, they still hatched and the spawn was successful.

[modealings]

Hm that's interesting. Thanks for the info. Now I wonder if I raised the tds too quickly and that caused them to die? I just went straight to tap after they hatched (270ppm).

[MD.David]

I don't think that would kill them, however I'm merely speculating, a more senior member with more experience might have a more definitive answer about that.
How quickly did they die?


Hm that's interesting. Thanks for the info. Now I wonder if I raised the tds too quickly and that caused them to die? I just went straight to tap after they hatched (270ppm).

[modealings]

Died at just about the 24 hour mark.

[MD.David]

So you raised the ppm and they died in 24hrs when they were just started swimming and feeding off of the mom and dad?
Do I understand this correctly?


Died at just about the 24 hour mark.

[modealings]

No they hatched, then I raised the tds with the first water change after hatching, then they died 24 hrs later. They never made it to the free swimming stage.

Sorry for the confusion - I understand that day 1 of free swimming is technically considered when they are born.

[MD.David]

What was your water changing regiment when they were still in the egg form?
Did the water change temp too?
Did you age your water prior to changing?
Usually they don't just die then they become wigglers with out something that caused it.
Do you have a digital thermometer on this tank?
Any clues might help.


No they hatched, then I raised the tds with the first water change after hatching, then they died 24 hrs later. They never made it to the free swimming stage.

Sorry for the confusion - I understand that day 1 of free swimming is technically considered when they are born.

[modealings]

The pair is in a 29 gal. I do 75-90% wc/day with matched temp, aged water. No digital thermometer, just a standard glass one.

My water is interesting bc the KH is quite low out of the tap (30-50) even with a tds of 270. I also get a very large pH swing with aging (9.1 to 7.2). I've been monitoring for pH crashes but with the daily wc's everything seems to be fine.

I've also been suspicious of gill flukes in the past few months. I treated with PP a few weeks or so ago but understand that these things can be quite pesky. I've havent confirmed with a microscope yet.

If anyone knows a good fish pathologist in Michigan, I could look into sending the dead fry there.

[MD.David]

Pretty interesting how they would die in mid wiggle.
Where they totally out of there shells?

[modealings]

Yea I'm not sure what happened. Either way I bleached everything, including the filter, and used PP on the fish. So we will see again next go around.

Also found these cool older videos explaining how the eggs swell/shrink in different TDS levels (with microscope pics). Haha the videos are hilarious bc they are so old but I think they had some good info.

https://m.youtube.com/watch?v=xarlybWecbs