Long Fin Zebra Danio Fell Ill and Died

[finbean3]

Friday morning, I observed our long fin (LF) zebra Danio hovering at the bottom of our 55 Gallon community aquarium. (See picture 3304 of aquarium) He appeared to be resting on the substrate and his gills were moving rapidly.

In this aquarium, we have other Danios (short fin zebra, long fin leopard, and 5 glofish), we have 8 glofish blackskirt tetras, 1 glofish shark, 2 nerite snails, some java moss, anubius barteri, java fern, pogostenum stellatus octopus, and various décor.

I observed a couple of the glofish Danios bother him and when they did, he would swim to another nearby section of substrate to resume his resting. From what I observed, the other Danios did appear to be a bit aggressive with him, but one of these Danios appeared to be chasing all the other Danios around too.

This was around 10am Friday morning when I first observed our LF Zebra Danio acting sick. The estimated water parameters I measured that morning were such:

The night before I added Easygreen, easy iron, and 10 Catappa leaves. Also, I replaced filter media and cleaned the filter sponge.

As noted in my table, the one thing I did Friday morning was to do a 10 Gallon water change with 2x dose prime, 3TBLS salt , 1x dose stability and pristine. Then I went to work and hoped for the best. When I left, I saw that our LF Zebra Danio had moved into the hide with our shark and was resting on the substrate there.

When I came home that evening, I found our LF Zebra Danio tangled in our Java Moss. So I freed him and decided it was time to move him to another aquarium. First, I tried to move him to our 40 Gallon breeder with our Mystery Snails, plants and sand substrate. However, after he kept resting on the sand, I thought better of it with his rapid gill movement. Maybe he would have been fine, but I thought it would be best to put him in our 20 Gallon aquarium to quarantine. At this point however, he was already showing signs of death as his body was arching into a bent shape and he was doing less and less swimming.

In the 20 Gallon, which I had about 15 gallons of water in, I changed 10 gallons with a double dose of prime and a single dose of stability. I have two medium sized sponge filters and a heater in this aquarium and I added 5 Tablespoons of Fritz aquarium salt. When I added our LF Zebra Danio, he was still sinking to the bottom and rapidly moving his gills. When I would move my hand toward him or a fishnet, he would swim up and I could get him swimming for a little bit, but soon he would just float back down and land on his side.

After leaving him for a bit, I tried adding an aquatic plant basket to the tank to use like a breeder box (see IMG_3367) and put him in it to try to get him up from the bottom of the aquarium. I added another airstone and tried feeding him some garlic fish food pellets which he seemed to take to when some fell near him. I upped the salt by adding another 5 tablespoons and I added 4 Catappa leaves to the basket. However, his situation didn't improve. I still saw his gills moving, but not as rapidly. You can see his disposition at this stage in IMG_3362.

After observing him like this for a bit longer, I took the plunge and added 5 more Tablespoons to  the aquarium to see if that would help. This was going to be my final addition of salt for a Level 3 treatment. However, I'm afraid that might have done him in, because his gills stopped moving after that. It is hard to say if he was on the way out anyway, but I wish I had left the salt at the original amount.

In a last ditch effort to correct my last salt dosage, I did another quick 10 gallon water change trying to suck up as much of the extra salt from the bottom of the aquarium as possible along with all the excess garlic food I dropped in and removed the basket and let him sink to the bottom of the aquarium. No sign of life. He is listless and I'm 95% positive he has given up the good fight.

If you have read this much, thank you for reading. I would love any advice, feedback, suggestions, insight. I'm happy to answer questions in the effort learn from this tragedy. While I think I'm learning some hard lessons, it would be good for me to hear from other fish keepers with more experience than myself. (I just started keeping fish in July of this year.)

[Colu]

It's difficult to say for sure as the onset of symptoms was very short period of time to his death what stands out is you have some ammonia and nitrite they are extremely toxic even in small amounts what I would do is test daily if you detect any ammonia or nitrite do a 50% water change and add a double dose of prime till it constantly stays at zero he could have been weak and the ammonia and nitrite been to much for him have how long have you had the long fin danios have you notice any rapid breathing hanging out near the surface lethargy flashing spitting food erratic swimming suken belly in any of your fish @finbean3

[finbean3]

Colu - my apologies for the late reply, but it has been a busy week. (I'm also incubating and hatching mystery snails, but I think those have been dying as well. Just learned how to clean the breeder box) 

Regarding the ammonia and nitrites, I have never measured anything lower than 0.1 ppm since I got the aquarium setup. Granted, these are my estimates based on how I read the test tubes and compare them visually with the reference booklet colors. So while I get that the goal is to keep the ammonia and nitrites down as much as possible, I don't think I will ever get down to zero. But I'm sure I could be doing better and so I appreciate the advice. 

I've had the long fin Zebra Danio since August 26th this year. I still have the short fin who appears to be a female since I see her belly. She and most of our remaining Danios appear to be fine with few exceptional notes: 

1) Our pink Glofish Danio does appear to have a bit of a sunken belly and has been spitting up food. Also appears to be smaller than the rest of his/her fellow Danios. It is hard to tell, but his/her eyes might be slightly swollen as well. I'm thinking this is the signs of bacterial disease. What do you think? (Picture attached) At present, I'm doing a 3rd Paracleanse treatment of the entire 55 gallon to rid any ensuing parasites. If our pink Glofish sustains, I'm thinking I will rest the fish for a couple weeks before treating the whole tank with another Maracyn treatment. Let me know if you have any advice or questions.

2) This isn't a disease, but I have noticed a couple of the largest Danios have been acting rather aggressive. The green Glofish Danio was noticeably aggressive around the LF Zebra Danio not only when he was dying, but in the past I noticed them acting more aggressive than usual. Normally I'm used to seeing the Danios chase each other around and based on my limited understanding of their behavior, I've always taken that as them schooling or just playing. However, I did take note that when these presumably male Danios were acting extra aggressive, our female Danios had slimmed down. I took this as a sign that they probably laid their eggs. I have a suspicion that there is a bit of male competition going on. I'm curious if there is anything to that. Of the 9 Danios we have had, I believe 3 were female and the rest I'm assuming to be male. When our LF Zebra Danio fell ill, I believe we only had 2 female Danios. (Our LF Leopard Danio and SF Zebra Danio) Also, our purple Glofish Danio appears to show similar aggressive behavior but to a lesser degree. To be fair, I could be misinterpreting the behavior. When I first added the Zebra Danios to the aquarium, they seemed to be getting along. 

3) I have not noticed rapid breathing from the remaining Danios. Also, I only noticed the rapid breathing from our LF Zebra Danio the day I saw him fall ill. Usually I see the Danios swimming around the bottom of the tank and then coming up to the top for food. In general, they seem to be all over the aquarium. I haven't noticed any flashing from them, but I suspect I just have not known what to look for. I occasionally see our Glofish Shark flashing, but I'm pretty sure that is due to a case of velvet that I see on him. Any insight on what Danios flashing looks like? I'll hit up google. 

Thank you for responding to my entry and for the advice and insight. I welcome more if you have the time.

[Colu]

On 11/17/2023 at 5:16 AM, finbean3 said:

Colu - my apologies for the late reply, but it has been a busy week. (I'm also incubating and hatching mystery snails, but I think those have been dying as well. Just learned how to clean the breeder box) 

Regarding the ammonia and nitrites, I have never measured anything lower than 0.1 ppm since I got the aquarium setup. Granted, these are my estimates based on how I read the test tubes and compare them visually with the reference booklet colors. So while I get that the goal is to keep the ammonia and nitrites down as much as possible, I don't think I will ever get down to zero. But I'm sure I could be doing better and so I appreciate the advice. 

I've had the long fin Zebra Danio since August 26th this year. I still have the short fin who appears to be a female since I see her belly. She and most of our remaining Danios appear to be fine with few exceptional notes: 

1) Our pink Glofish Danio does appear to have a bit of a sunken belly and has been spitting up food. Also appears to be smaller than the rest of his/her fellow Danios. It is hard to tell, but his/her eyes might be slightly swollen as well. I'm thinking this is the signs of bacterial disease. What do you think? (Picture attached) At present, I'm doing a 3rd Paracleanse treatment of the entire 55 gallon to rid any ensuing parasites. If our pink Glofish sustains, I'm thinking I will rest the fish for a couple weeks before treating the whole tank with another Maracyn treatment. Let me know if you have any advice or questions.

2) This isn't a disease, but I have noticed a couple of the largest Danios have been acting rather aggressive. The green Glofish Danio was noticeably aggressive around the LF Zebra Danio not only when he was dying, but in the past I noticed them acting more aggressive than usual. Normally I'm used to seeing the Danios chase each other around and based on my limited understanding of their behavior, I've always taken that as them schooling or just playing. However, I did take note that when these presumably male Danios were acting extra aggressive, our female Danios had slimmed down. I took this as a sign that they probably laid their eggs. I have a suspicion that there is a bit of male competition going on. I'm curious if there is anything to that. Of the 9 Danios we have had, I believe 3 were female and the rest I'm assuming to be male. When our LF Zebra Danio fell ill, I believe we only had 2 female Danios. (Our LF Leopard Danio and SF Zebra Danio) Also, our purple Glofish Danio appears to show similar aggressive behavior but to a lesser degree. To be fair, I could be misinterpreting the behavior. When I first added the Zebra Danios to the aquarium, they seemed to be getting along. 

3) I have not noticed rapid breathing from the remaining Danios. Also, I only noticed the rapid breathing from our LF Zebra Danio the day I saw him fall ill. Usually I see the Danios swimming around the bottom of the tank and then coming up to the top for food. In general, they seem to be all over the aquarium. I haven't noticed any flashing from them, but I suspect I just have not known what to look for. I occasionally see our Glofish Shark flashing, but I'm pretty sure that is due to a case of velvet that I see on him. Any insight on what Danios flashing looks like? I'll hit up google. 

Thank you for responding to my entry and for the advice and insight. I welcome more if you have the time.

A sunken belly and spitting food out can be a sign of wasting disease and you would want to treat with levamisole active ingredient in expel p once a week for 4 weeks ammonia and nitrite test kit could be zero it's difficult to tell with subtle colour change