Unexpected glowlight danio spawn!

[Andy Sager]

I've been giving her epsom salt baths every morning and starving her in case it was constipation (I feed the others while she's in the bath). No change unfortunately I also gave her a boiled green bean (just the inner "pea" part) as I had no peas, and she ate it but she's still really round. Poor girl. I'll try some live brine shrimp tonight.

Should I put her in her own tank / container and monitor to see if she poops? I saw some white / clear poops on the tank bottom a while after the first time I gave her an epsom salt bath but I don't know if that was her, the snails, or the other fish.

The best way to know is by isolating the fish and having a bare bottom so you can see what is coming out of the fish. If it is constipation, you don't want to not feed her because you want the new poo to push out the old poo. Just feed her high roughage foods like the peas/beans, brine shrimp or bloodworms tho. No dry or freeze dried foods.

 

[Lycanthi]

I've given them brine shrimp but it looked like the male got most of it, he's really a bit of a bully. I'm giving them green beans today.

The larger fry actually look like miniature fish now. They have tiny anal fins and dorsal fins (hard to see in photos) and are starting to go yellowish. No red line yet (supposedly they should look like glowlight tetras at a certain point with a glowing orange / red line). The largest ones are about 8-10mm long.




I'm hoping to get at least six to adulthood. Currently have around 24 fry in total but a few have bent spines so I expect those will die off, and others don't look like they are growing much (if at all).

I noticed that the larger ones are swimming much lower in the water column (the smaller ones stick to the surface) and are hunting tiny worms near the bottom and on the sides of the tank. They ignore brine shrimp still but seem to love eating whatever the tiny worms are (rabdocoela?).

Their parents are still spawning every couple of days or so.

I found more danio fry in my unheated display tank too so I suppose glowlight danios don't really need warmer temps to spawn (the unheated tank varies from 19 - 21 C at the moment).

 

[Andy Sager]

Congrats on getting this far.
For what it's worth, the ones with the bent spines may not just perish on their own so if you want to not have them anymore, they should be euthanized. It's not unusual, sadly, to see fish with bent spines in fish stores because the farms didn't take the time to cull those fish. In your case, all you are doing is feeding fish that should have no future in your tank(s). You definitely do not want to breed those fish as whatever caused the bending could be genetic and you certainly don't want to pass those genes on.

 

[Lycanthi]

Congrats on getting this far.
For what it's worth, the ones with the bent spines may not just perish on their own so if you want to not have them anymore, they should be euthanized. It's not unusual, sadly, to see fish with bent spines in fish stores because the farms didn't take the time to cull those fish. In your case, all you are doing is feeding fish that should have no future in your tank(s). You definitely do not want to breed those fish as whatever caused the bending could be genetic and you certainly don't want to pass those genes on.

Thank you these fry are certainly more work than my krib fry were - for them I just added egg yolk for the first week and then quickly moved them onto ground flake food, but they were so much larger to start with. They also grazed the substrate or surfaces to eat so it was very easy to target feed them - just covered the coconut shell that was their cave in egg yolk or flake particles and their parents would herd them up there to graze. Later the parents would chew up full size flakes and spit out the smaller pieces for them to eat too. At one point the male even produced a slime coat for them to feed on (I didn't realize kribs did this until I saw it).

These danio fry are so much harder to feed without fouling the water as they only feed from the water column when first free swimming (have to put more food than necessary to keep it suspended). It takes a few days for them to realize there's a surface and start eating off that, and weeks apparently for them to realize there's a bottom of the tank and start feeding from that xD it's definitely really cool to watch them go through all the developmenal stages though.

The ones with bent spines aren't swimming very well so I suspect they won't get enough food to grow to adulthood. I suppose it's less cruel to cull them quickly. I don't like killing fish directly but I could feed them to my barb to cull the deformed ones? As long as that doesn't risk disease being spread (bent spine in fry is likely genetic right? Not disease).

 

[Andy Sager]

Thank you these fry are certainly more work than my krib fry were - for them I just added egg yolk for the first week and then quickly moved them onto ground flake food, but they were so much larger to start with. They also grazed the substrate or surfaces to eat so it was very easy to target feed them - just covered the coconut shell that was their cave in egg yolk or flake particles and their parents would herd them up there to graze. Later the parents would chew up full size flakes and spit out the smaller pieces for them to eat too. At one point the male even produced a slime coat for them to feed on (I didn't realize kribs did this until I saw it).

These danio fry are so much harder to feed without fouling the water as they only feed from the water column when first free swimming (have to put more food than necessary to keep it suspended). It takes a few days for them to realize there's a surface and start eating off that, and weeks apparently for them to realize there's a bottom of the tank and start feeding from that xD it's definitely really cool to watch them go through all the developmenal stages though.

The ones with bent spines aren't swimming very well so I suspect they won't get enough food to grow to adulthood. I suppose it's less cruel to cull them quickly. I don't like killing fish directly but I could feed them to my barb to cull the deformed ones? As long as that doesn't risk disease being spread (bent spine in fry is likely genetic right? Not disease).

Yeah, danio fry are much different than cichlid fry. From size to parenting to growth rate to foods, it's all different.
As for what to do with the crookeds, there are a few reasons fry develop those crooked spines. Genetics, water quality, vitamin deficiency and disease being the main ones. So the chance of these fry carrying a disease is possible but by nature, fish eat the dead, infirmed old and diseased fish out in the wild so there is the possibility that nothing will happen if you feed them to your barbs or they too can now carry whatever the disease is. Since these fish are new to you, there will not be any definitive answer to the cause as you don't know what they went through before you got them.
For me, I put everything else out of my mind and just ask this question: " What is the best thing to do for the fish colony?" 99.99999999999% ( because nothing is 100% ) the answer is "get rid of them." If you don't want to chance the cause being disease, don't feed them to other fish. If you are willing to possibly losing your Barbs, feed them to the Barbs. Just be sure to be okay with whatever happens from your decision. When it comes to breeding, culling is an important part of the process. We have taken away the natural ways these deformed and diseased fish are gotten rid of in nature so you have to play Mother Nature in order to keep the fish stock healthy. Just look at all the balloon fish and deformed fish that are now part of the hobby because the breeder didn't want to cull them. The fish suffer shorter lifespans, internal disfunctions, reproductive issues and more. Talk about not being fair to the fish.... That's just the cold hard facts.

Hope this helps.

 

[Lycanthi]

Yeah, danio fry are much different than cichlid fry. From size to parenting to growth rate to foods, it's all different.
As for what to do with the crookeds, there are a few reasons fry develop those crooked spines. Genetics, water quality, vitamin deficiency and disease being the main ones. So the chance of these fry carrying a disease is possible but by nature, fish eat the dead, infirmed old and diseased fish out in the wild so there is the possibility that nothing will happen if you feed them to your barbs or they too can now carry whatever the disease is. Since these fish are new to you, there will not be any definitive answer to the cause as you don't know what they went through before you got them.
For me, I put everything else out of my mind and just ask this question: " What is the best thing to do for the fish colony?" 99.99999999999% ( because nothing is 100% ) the answer is "get rid of them." If you don't want to chance the cause being disease, don't feed them to other fish. If you are willing to possibly losing your Barbs, feed them to the Barbs. Just be sure to be okay with whatever happens from your decision. When it comes to breeding, culling is an important part of the process. We have taken away the natural ways these deformed and diseased fish are gotten rid of in nature so you have to play Mother Nature in order to keep the fish stock healthy. Just look at all the balloon fish and deformed fish that are now part of the hobby because the breeder didn't want to cull them. The fish suffer shorter lifespans, internal disfunctions, reproductive issues and more. Talk about not being fair to the fish.... That's just the cold hard facts.

Hope this helps.

Well, the balloon fish isn't due to not wanting to cull, it was greed: "hey that looks different, I wonder if people will pay more for that?" and then deliberately selecting the most ballooned fish to breed on. Much the same way we ended up with deformed dogs like pugs, dachshunds or bulldogs, and deformed cats like persians and Scottish folds. I think out of all fish, goldfish have suffered the most from this - the bubble eye ones make me feel ill.

I'll think about how to cull humanely. I definitely don't want to propagate disabled fish.

 

[Andy Sager]

Well, the balloon fish isn't due to not wanting to cull, it was greed: "hey that looks different, I wonder if people will pay more for that?" and then deliberately selecting the most ballooned fish to breed on. Much the same way we ended up with deformed dogs like pugs, dachshunds or bulldogs, and deformed cats like persians and Scottish folds. I think out of all fish, goldfish have suffered the most from this - the bubble eye ones make me feel ill.

I'll think about how to cull humanely. I definitely don't want to propagate disabled fish.

We'll have to agree to disagree on the reason. I had balloon fish in the 1960s and they ended up in the stomachs of my Oscars. Poor breeding lines produced more of them so the farms didn't want to lose all that money so they "made them" a got to have fish instead of a got to get rid of fish. There has been many attempts to change the appearance of fish over the decades and some of those attempts have lead to oddballs ( i.e Balloon fish, AngelRams, Glo-fish) and some have lead to Colored Swordtails, Delta Tail Guppies and Veiltailed Angelfish, etc. Some have remained in the hobby and some have disappeared. There is a whole list of fish that I kept and bred in the 60s and 70s that are no longer seen in the hobby. Why? It's either the demand for them was not there or, and sadly this is a human foible imo, people believe that NEW is better. ( Glo-fish are a perfect example of this. )
As for dogs and cats, they too have suffered the effects of trying to create new breeds. For example: so many of the TOY brands of dogs have internal issues. Some of the Labs/Retrievers have genetic hip issues. Dachsunds have back issues. The list is long. A number of years ago I was watching a program on dog breeds and the program noted that from the chart of all species of AKC recognized breeds at the time, 25% of them no longer existed as of the program date. So once again, it's the human "idea" that " new is better" imo. Thankfully the 2 breeds my parents bred ( Weimaraners, and Australian Terriers) are still going strong.

 

[Lycanthi]

We'll have to agree to disagree on the reason. I had balloon fish in the 1960s and they ended up in the stomachs of my Oscars. Poor breeding lines produced more of them so the farms didn't want to lose all that money so they "made them" a got to have fish instead of a got to get rid of fish. There has been many attempts to change the appearance of fish over the decades and some of those attempts have lead to oddballs ( i.e Balloon fish, AngelRams, Glo-fish) and some have lead to Colored Swordtails, Delta Tail Guppies and Veiltailed Angelfish, etc. Some have remained in the hobby and some have disappeared. There is a whole list of fish that I kept and bred in the 60s and 70s that are no longer seen in the hobby. Why? It's either the demand for them was not there or, and sadly this is a human foible imo, people believe that NEW is better. ( Glo-fish are a perfect example of this. )
As for dogs and cats, they too have suffered the effects of trying to create new breeds. For example: so many of the TOY brands of dogs have internal issues. Some of the Labs/Retrievers have genetic hip issues. Dachsunds have back issues. The list is long. A number of years ago I was watching a program on dog breeds and the program noted that from the chart of all species of AKC recognized breeds at the time, 25% of them no longer existed as of the program date. So once again, it's the human "idea" that " new is better" imo. Thankfully the 2 breeds my parents bred ( Weimaraners, and Australian Terriers) are still going strong.

Yes, it's sad what people will do to animals for fashions or fads.

I try to keep animals that haven't been heavily selectively bred. I prefer the wild type colouration over the domestic colouration for most species. When I kept guppies I deliberately sought out "mutts" so they were closest to the original wild type colours. Mutt / wildtype guppies are as pretty as endlers imo.

Small update: the fry are still growing and some of the weaker / deformed ones have perished. There's now 20 fry but I'm guessing around 10 that look healthy, big, and strong enough to make it to juveniles.

I finally found the time to clean out my empty 5 gallon that has been sitting outside for over a year - it took a lot of effort, vinegar and hydrogen peroxide to get it squeaky clean and disinfected. I'm going to set up the 5g as a grow out tank tonight. I'm not sure if I should put a thin layer of sand on the bottom or not? Would bare bottom be better? I have a small sponge filter in the QT that I can move over to the 5g, and I can put some plants in as decor and nitrate control.

Will the 5g be large enough for 10-20 danio fry to reach a safe size to go with adult fish?

 

[Andy Sager]

Yes, it's sad what people will do to animals for fashions or fads.

I try to keep animals that haven't been heavily selectively bred. I prefer the wild type colouration over the domestic colouration for most species. When I kept guppies I deliberately sought out "mutts" so they were closest to the original wild type colours. Mutt / wildtype guppies are as pretty as endlers imo.

Small update: the fry are still growing and some of the weaker / deformed ones have perished. There's now 20 fry but I'm guessing around 10 that look healthy, big, and strong enough to make it to juveniles.

I finally found the time to clean out my empty 5 gallon that has been sitting outside for over a year - it took a lot of effort, vinegar and hydrogen peroxide to get it squeaky clean and disinfected. I'm going to set up the 5g as a grow out tank tonight. I'm not sure if I should put a thin layer of sand on the bottom or not? Would bare bottom be better? I have a small sponge filter in the QT that I can move over to the 5g, and I can put some plants in as decor and nitrate control.

Will the 5g be large enough for 10-20 danio fry to reach a safe size to go with adult fish?

Bottom stuff is personal preference. Some sand will show any detritus that needs to be removed a bit better than a bare bottom unless the tank is sitting on something light colored that will show through the bottom glass. Another up side to using some sand is for your plants and places for any nitrifying microbes to adhere to if there is enough oxygenation going through it.
The 5 gal will work for a while but I doubt 10-20 fry will grow to adult in there unless you are doing large volume water changes almost daily. I'll bet that getting a 10 gal when the box stores have the $1/ gallon sales will end up being less money than doing all the work in the 5. Space and water quality grows fish fry better.

 

[Lycanthi]

Bottom stuff is personal preference. Some sand will show any detritus that needs to be removed a bit better than a bare bottom unless the tank is sitting on something light colored that will show through the bottom glass. Another up side to using some sand is for your plants and places for any nitrifying microbes to adhere to if there is enough oxygenation going through it.
The 5 gal will work for a while but I doubt 10-20 fry will grow to adult in there unless you are doing large volume water changes almost daily. I'll bet that getting a 10 gal when the box stores have the $1/ gallon sales will end up being less money than doing all the work in the 5. Space and water quality grows fish fry better.

Heh unfortunately in Europe you can't get aquariums for the equivalent of $1 a gallon. The cheapest I've found is €27 for 10 gallons without a lid. Which would be fine, but I'm also pressed for space to put aquariums on. I don't have a large house, just a 2 bed apartment and my partner wouldn't enjoy every surface covered in tanks as much as I would lol.

I dont expect them to get to adult size in the 5g but just large enough not to be eaten by the adult fish. Not sure what size that would be... half the length of the adult fish perhaps?

 

[Andy Sager]

Heh unfortunately in Europe you can't get aquariums for the equivalent of $1 a gallon. The cheapest I've found is €27 for 10 gallons without a lid. Which would be fine, but I'm also pressed for space to put aquariums on. I don't have a large house, just a 2 bed apartment and my partner wouldn't enjoy every surface covered in tanks as much as I would lol.

I dont expect them to get to adult size in the 5g but just large enough not to be eaten by the adult fish. Not sure what size that would be... half the length of the adult fish perhaps?

Ahhh, I forgot you weren't in the U.S. They need to get to larger than the mouths of the other fish and fast at feeding before they are safe in with the adults.