Glowlight Eggs Keep Fungussing

[bobfloyd]

Hi,

I have spawned glowlights in a breeding tank serveral times now and every time the eggs fungus. Is there anybody there that is experienced at breeding glowlights that can give me some advice? The water has a GH of 5 degrees and a KH of 3 degrees. pH is around 6.5 -7.0. Tank sterilised with salt beforehand. I'm putting 1 female and 2 males in the tank.

Bob.

 

[The-Wolf]

glowlights, what golwlights?
danio, rasbora or tetra?

all the same the most commonly used method for preventing fungus on eggs is methylene blue
although more and more people these days use melafix

 

[bobfloyd]

They are glowlight tetras. I have tried putting some methylene blue in the water and have also covered the tank whilst spawning to keep things nice and dark. I think the eggs are fungussing because they are not being fertilised? How old do the males need to be?

glowlights, what golwlights?
danio, rasbora or tetra?

all the same the most commonly used method for preventing fungus on eggs is methylene blue
although more and more people these days use melafix

 

[Lateral Line]

Glowlight Tetras are sexually mature at about 8 months, but the yields at that age are low. With small tetras like that, I usually breed them after a year and then some, typically 14 months. That said, a lot depends on the conditions.

 

[bobfloyd]

Hi. Thanks for that info - so you have successfully bred glowlights before? This is the procedure that I am following, tell me what you think:

I keep the female glowlights in one tank (with some other female tetras that I am also breeding), and I keep the males in another tank (with the corresponding males for the other tetras). I keep the water in each tank nice and warm and clean with an acidic pH. I feed the fish frozen blood worms, live mosquito larvae, fish scrapings, flake and pellets (several brands). I set up a small spawning tank (contains about 10 litres of water) with a plastic home-made spawning grid on the bottom (made from some pvc pipe to make a square covered with plastic mesh) a spawning mop made out of knitting wool attached to a cork float placed over the spawning grid, a heater, and an open ended airline (I don't bother with a filter yet, not until there are valid eggs in their, then I'd put in a small sponge filter). I also put a small heater in the tank to keep things steady.

I cover the back and sides of the tank with cardboard and the top with a dark towel (thanks for the tip Big J, but I'm already keeping the tank fairly dark). I keep a thermometer in the tank to keep tabs on the temperature.

I have tried various types of water. I have tried a 50-50 mix of bottled distilled water with dechlorinated tap water and I have also tried 100% water from the parents tanks.

I put a fat female and a couple of males in the tank just before I go to bed and the next day there are eggs in the tank, heaps of them.

But - EVERY single time without fail they have all fungussed! It is very frustrating!

Perhaps the males are too young? Some sources say that the males need to be 6 months old whereas the pet shop says they can breed from 2-3 months?
I have had the fish since Christmas so they are at least 3 months old. If they were say 2-3 months old in the shop already at Christmas that means they would possibly be getting close to 6 months old by now. Hmmm. Do males still go through the motions, so to speak, even if they are too young to actually produce sperm and fertilise the eggs?

How do you know that 8 months is when they are sexually mature? It would be good to know that kind of information, none of the books that I have on fish go into that level of detail. I'm interested in knowing whether the males can go through the motions even if they aren't mature?

It seems unusual that I fish that has only a short lifespan (a couple of years for a glowlight?), wouldn't be at it's breeding peak until it's around 14 months old - I mean - wouldn't nature dictate that this animal should breed younger? My local pet shop told me they can breed at 2 -3 months of age!

Now I'm really confused!

Bob.

Glowlight Tetras are sexually mature at about 8 months, but the yields at that age are low. With small tetras like that, I usually breed them after a year and then some, typically 14 months. That said, a lot depends on the conditions.

 

[Lateral Line]

I make spawning mops from nylon, not wool. I find it lasts longer and is much easier to clean between spawnings. My spawning tanks are regular 24x12x12 usually half filled for small species. I usually breed with just the pair, female in at lunch time, male in last thing in the evening and tank darkened, rarely fail to spawn next morning when the covers are removed. My single sex tanks have 4-5 sponge filters in each so I have a ready supply of well matured sponges for the fry tanks when they hacth, a good sponge will be covered with rotifers and all manner of small things the fry can eat. You sound like you are doing much the same as I though from a procedural point of view.

I say 8 months because that is how old my breeders were when I first got a succesful spawning. Under good water conditions in a stress free environment, Glowlights and many other small tetras will live 4-5 years. It is usually water chemistry that kills them early, also that which prevents eggs hatching. This could be your issue.

Most of the small tetras come from very soft water, some, the blackwater fish from the Rio Negro basin etc., come from water with virtually no dissolved salts at all. When I was in the Rio Negro basin, in the backwater creeks, the water was to soft to measure, and in some places, was more acidic then I could measure, i.e. lower then pH4.

What happens in tapwater in most places is that the balance between the body electrolytes and the environment is difficult to maintain. The organ that is hardest hit is the kidney, it has to work really hard to keep the elctrolyte balance right, and wears out. Thus softwater fish that "are fine" in tapwater are in actual fact chemically stressed and frequently die young from kidney failure.

Similarly, the eggs have evolved to ambient conditions. What tends to happen in harder water is Calcium ions react with the egg shells. The fry develop normally, but when the are ready to hatch, the shell has become to tough for them to break out, so they die.

You say you are keeping your water acidic, but how are you doing this? What are your water parameters, particularly hardness? I have a reverse osmosis unit for producing very soft water.

 

[bobfloyd]

Hi Lateral Line,

When you say they were 8 months old before they bred successfully, what do you mean by successfully? Do you mean that they actually layed eggs (i.e. they spawned) or do you mean they spawned and the eggs were fertile? Do you know if it's possibly for tetras to spawn, i.e. go through the motions, but for the male to be too immature to actually fertilise the eggs? I would think that if the fish were too young they wouldn't even lay eggs at all? My fish are spawning, heaps of eggs, but none of them appear fertile. Does this mean the male is not too young, or could he still be too young but just "going through the motions" anyway. I hope my question there is clear.

My tapwater has a GH of 5 degrees and a KH or 3 degrees. I have tried diluting it with bottled distilled water, 50-50 (so roughly 2.5 GH and 1.5 KH). How soft the water has to be is confusing. Some literature says anywhere up to 8 degrees GH is fine, in which case, my tap water would be fine as is. What are your thoughts?

In any case, I assume it is only the breeding tank water that is of the most importance? The fish are filling up with eggs in the conditioning tanks, so I assume the water is fine there at that the eggs are good while inside the females body?

Thanks for your help,
Bob.

I make spawning mops from nylon, not wool. I find it lasts longer and is much easier to clean between spawnings. My spawning tanks are regular 24x12x12 usually half filled for small species. I usually breed with just the pair, female in at lunch time, male in last thing in the evening and tank darkened, rarely fail to spawn next morning when the covers are removed. My single sex tanks have 4-5 sponge filters in each so I have a ready supply of well matured sponges for the fry tanks when they hacth, a good sponge will be covered with rotifers and all manner of small things the fry can eat. You sound like you are doing much the same as I though from a procedural point of view.

I say 8 months because that is how old my breeders were when I first got a succesful spawning. Under good water conditions in a stress free environment, Glowlights and many other small tetras will live 4-5 years. It is usually water chemistry that kills them early, also that which prevents eggs hatching. This could be your issue.

Most of the small tetras come from very soft water, some, the blackwater fish from the Rio Negro basin etc., come from water with virtually no dissolved salts at all. When I was in the Rio Negro basin, in the backwater creeks, the water was to soft to measure, and in some places, was more acidic then I could measure, i.e. lower then pH4.

What happens in tapwater in most places is that the balance between the body electrolytes and the environment is difficult to maintain. The organ that is hardest hit is the kidney, it has to work really hard to keep the elctrolyte balance right, and wears out. Thus softwater fish that "are fine" in tapwater are in actual fact chemically stressed and frequently die young from kidney failure.

Similarly, the eggs have evolved to ambient conditions. What tends to happen in harder water is Calcium ions react with the egg shells. The fry develop normally, but when the are ready to hatch, the shell has become to tough for them to break out, so they die.

You say you are keeping your water acidic, but how are you doing this? What are your water parameters, particularly hardness? I have a reverse osmosis unit for producing very soft water.

 

[NEONCORY]

Hey Bob,

I know most of the fish the female sexually mature faster than the male. And the female would fill with roes. That is why your hatch rate would improve as your fish get older. And yes, they will still produce eggs even the male is not yet capable of fertlize eggs.
And like I said, I don't have test for the hardness. I don't have R.O but I do manage to get frys from Neons with half distilled and half peat soaked tap water. And as we all know, the Neon require softer than Glowlight. I can't imagine your 5GH and 3KH would be the reason of eggs not hatching.
And you seems doing right for the covering the light out and such. So I still think the cause would be either the male(s) are too young(not sexually matured) or some medication made them sterile.
If the case of the male(s) are too young, you just have to wait little longer or go find matured male(s).
Just keep trying and I'm sure you'll get the frys from Glowlight. Good luck.

 

[Lateral Line]

A success for me is when I raise the fry. I have had some fish go through the motions of spawning without producing fry, the same fish later were successful. Other species, (I have a long story about Barbus johorensis), simply swam around the breeding tank, (a larger tank then I'd use for GLowlights of course), this despite them being full size, and in peak condition.

In this case, your water appears to be okay. Glowlights are not that difficult to breed. I guess you're males are not fertilizing the eggs. Leave it a few months and try them again.

*** EDIT ***

We seem to have been typing at the same time!

I agree, it all seems to be right. It's the fertility of the males that seems in question.

 

[bobfloyd]

Hi Neoncory/Lateral Line,

Thanks very much guys for your thoughts and help, much appreciated. I will continue feeding up the male and female glowlights but I'll give it a month and try them again. In the meantime, I'll work on the black neon tetras and lampeyes that I also have in conditioning tanks. Actually, I will post a question about my black neons shortly, you may be able to help me with that too. ;-)

I'll let you know how I go with the glowlights when I try them again in a about a month's time, perhaps the males will be mature enough then.

Take care,
Bob.

A success for me is when I raise the fry. I have had some fish go through the motions of spawning without producing fry, the same fish later were successful. Other species, (I have a long story about Barbus johorensis), simply swam around the breeding tank, (a larger tank then I'd use for GLowlights of course), this despite them being full size, and in peak condition.

In this case, your water appears to be okay. Glowlights are not that difficult to breed. I guess you're males are not fertilizing the eggs. Leave it a few months and try them again.

*** EDIT ***

We seem to have been typing at the same time!

I agree, it all seems to be right. It's the fertility of the males that seems in question.

 

[NEONCORY]

You are welcome Bob,

Good luck with other Tetras. Unfortunately I haven't bred many Tetras, I only have done with Glowlight and Neons and unassisted Lemon Tetras(they did it in the community and some survivors poped up). I may try Blue Tetras soon as soon as I get some and condition them. I did Neon about 2 weeks ago and have some free-swimming frys but it was not big batch so tried again 2 days ago and got some eggs yesterday. They should hatch sometime late today or tomorrow.
I heard that if you can breed Neons or Cardinals, you can breed most of the other Tetras. Especially if you learn how to raise those tiny frys, ou should be able to raise almost any Tetras. To me, raising small frys are the most toughest part. Hatching eggs is just matter of water condition and egg condition(like your case). And getting eggs are just matter of fish condition and some compatability.
I don't breed Tetras often since it require pretty constant care in the beggining(feeding, water maintenance). But I do Neons since they are my favorite and if I have some tank space, they can fill up the tank with color.
Anyway, good luck with all the Tetras. To me, it is so satisfying and sense of accomplishment since they require some attention to details and tender care.

BTW, did you block me on the PM? I don't care if you did but I just curious if it is you or my PM system have problem.

 

[bobfloyd]

Hi Neoncory,

Cool - thanks for the help. I will try breeding neons at some stage and will ask you for some advice when the time comes. I will keep you posted how I go with the glowlights.

I definitely didn't block you from PM. Must be something your end?

Bob.

You are welcome Bob,

Good luck with other Tetras. Unfortunately I haven't bred many Tetras, I only have done with Glowlight and Neons and unassisted Lemon Tetras(they did it in the community and some survivors poped up). I may try Blue Tetras soon as soon as I get some and condition them. I did Neon about 2 weeks ago and have some free-swimming frys but it was not big batch so tried again 2 days ago and got some eggs yesterday. They should hatch sometime late today or tomorrow.
I heard that if you can breed Neons or Cardinals, you can breed most of the other Tetras. Especially if you learn how to raise those tiny frys, ou should be able to raise almost any Tetras. To me, raising small frys are the most toughest part. Hatching eggs is just matter of water condition and egg condition(like your case). And getting eggs are just matter of fish condition and some compatability.
I don't breed Tetras often since it require pretty constant care in the beggining(feeding, water maintenance). But I do Neons since they are my favorite and if I have some tank space, they can fill up the tank with color.
Anyway, good luck with all the Tetras. To me, it is so satisfying and sense of accomplishment since they require some attention to details and tender care.

BTW, did you block me on the PM? I don't care if you did but I just curious if it is you or my PM system have problem.