Rainbow shark devastation. What’s next?

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

jbodnar22

Aquarium Advice Apprentice
Joined
Jan 4, 2025
Messages
10
Location
mount holly, NJ
Hi there, new here. I have been to multiple other forums and Facebook pages and local fish stores for help. First I want to note that ALL tank parameters are exactly as they should be. Any pictures that appear to be “cloudy” are either do to my phone, or pictures/videos taken after a feeding (fish will come out more with food present lol), or even a medication in the tank. This has been going on for about a month.
Just need help identifying what the issue could be. It seems to only be affecting my rainbow sharks like this. (I’ve noticed some abnormalities on my other fish but I think I’m just paranoid, none of the others have anything that look like this). So far treatments done are:
Aquarium salt, Aquarian Melacure, Seachem ParaGaurd, Tetra Lifegaurd, small round of Jungle Ick clear (mainly for the active ingredient, not because they have ick). I e treated for fungal infections, bacterial infections and diseases, and parasites. No improvement. Started as a small red spot, treated as an injury, then developed bigger and eventually into a fungus cotton like growth, which eventually leaves a deep hole, then follows up with death. developed mainly behind the gills on one side of the fish. With one developing it in-between the bottom fins, and the orange shark developing it in TWO spots, behind a gill but further up, and near the base of tail. So far 2 have died. Sorry for the long read, but thank you if you are still here. Asking very respectfully for no accusations of bad water conditions, fish bullying, or personal opinions of diagnosis unless you feel it could really really be it and/or are experienced!
 

Attachments

  • IMG_9475.jpeg
    IMG_9475.jpeg
    158.1 KB · Views: 1
  • IMG_9474.jpeg
    IMG_9474.jpeg
    133.7 KB · Views: 1
  • IMG_9476.jpeg
    IMG_9476.jpeg
    100.8 KB · Views: 1
  • IMG_9524.jpeg
    IMG_9524.jpeg
    148.1 KB · Views: 1
  • IMG_9533.jpeg
    IMG_9533.jpeg
    76.6 KB · Views: 1
  • IMG_9529.jpeg
    IMG_9529.jpeg
    87.6 KB · Views: 2
  • IMG_9502.jpeg
    IMG_9502.jpeg
    170.4 KB · Views: 2
  • IMG_9545.png
    IMG_9545.png
    443.3 KB · Views: 2
  • IMG_9546.png
    IMG_9546.png
    512.8 KB · Views: 1
Hello and welcome to the site. :flowers:
For starters, Rainbow sharks are highly territorial with members of their own kind as well as other shark species so there should never have been more than one in the tank at a time. Your tank appears to have very little " floor space" so that's problem #2 for multiple rainbow sharks in a tank.
Because these fish are farmed, the possibility of internal worms and tumors is there. Some of the spots appear to be the beginnings of a worm hole where the worm is trying to escape the fish. See Pics 9474, 9545 and 9476. None of the medications you listed would treat something like this. Sechem paraguard treats external parasites. You would have needed to use one for internal parasites.
Additionally, since we are talking about multiple sharks in a smaller sized aquarium, the most likely cause is from aggression between the sharks. The "fungus cotton like growth" is a general response to an injury. None of the medications you listed are the correct ones for treating fungus I believe. Fungus is best treated with Fluconazole when on fish. I'm unfamiliar with some of the meds you mentioned but I didn't see Fluconazole in their ingredients. Also, fungal growth usually occurs on injuries when the water is not the cleanest. You say your water parameters are " exactly as they should be" but diseases have tell tale signs. Unless your ammonia, nitrite and nitrates are at zero, they are not where they should be, they may be where they are exceptable to most fish but that does not mean they are where they should be. Just sayin' ;)
I would do some nighttime observations of these sharks. After the light goes out, check the tank out at certain intervals to see if the sharks are fighting each other. Use a flashlight and observe from a distance. Also, look for a shark with no or the fewest injuries. This one would likely be " the boss" and the one I would keep and rehome the rest of them. That or each fish would need to be treated in their own hospital tank so that they can heal up.
Hope this helps. (y)
 
So contrary to belief, I have had the same 5 rainbows together for 2 years now with no issues of bullying, territory aggression, etc at all thankfully. I have multiple cave and tunnel type pieces that they all took into liking and have always been quite docile around each other and the other fish. (I do have other tanks I was rearranging and moved some of the sharks out, but stopped as soon as this situation started, I immediately pulled the moved sharks and into hospital tanks with no prevail for them either and the other fish in those tanks seem unaffected as well) Unfortunately, all of the rainbows have these sores/ulcers/whatever you want to call ems, have appeared over a 3-4 weeks time frame.
I appreciate the info on the meds, I guess the medications are misleading due to packaging being labeled as a fungal treatments, parasite treatments, etc. but I will keep an eye out for that type of active ingredient.
And parameters have been pretty spot on as I am active with the tanks I have. I had a water sample tested as well at my local fish store.
Last, the worms you mentioned, is that something that would happen even after having them for over 2 years?? Especially for them to all go through it within the same window of time and not affect the other tank mates?
 
So contrary to belief, I have had the same 5 rainbows together for 2 years now with no issues of bullying, territory aggression, etc at all thankfully. I have multiple cave and tunnel type pieces that they all took into liking and have always been quite docile around each other and the other fish. (I do have other tanks I was rearranging and moved some of the sharks out, but stopped as soon as this situation started, I immediately pulled the moved sharks and into hospital tanks with no prevail for them either and the other fish in those tanks seem unaffected as well)
Unfortunately, these genetically altered fish seem to be prone to certain issues. For example, Tumors are quite common on them it seems. ( There are a lot of posts on here about tumors and the fish are mostly Goldfish and Glo-fish. ) There's nothing that can be done for tumors. :( If the sharks were smaller when you got them, that may account for them getting along but they are larger now and the space did not grow. They may be becoming sexually mature now so the fighting is for breeding rights. You may also just have gotten lucky and your luck has run out. :unsure:
Unfortunately, all of the rainbows have these sores/ulcers/whatever you want to call ems, have appeared over a 3-4 weeks time frame.
Bottom fish are very prone to getting parasitic infestations because these parasites will lay their eggs in the substrate then when they hatch, they go into the nearest fish they can get hold of. Catfish are also big carriers of worms. If the sharks were grown out in mud pools ( which is quite common in Asia), they could easily have come to you infected. There are also parasites that use things like fish or snails or amphibians as intermediate hosts because they need the animals that eat these to complete their life cycles. With that, these parasites do not usually harm the host because they need the host for the transfer.
Because all the sharks were effected in a relatively short amount of time, if that's not from fighting, that points to a water chemistry issue or something that caused a change in the chemistry of the fish's cells that if these were worms, caused the worms to want to find a new host in cleaner water. If it were just their natural time to leave a fish, I can safely say that it would not be happening at the same time on different fish.
I appreciate the info on the meds, I guess the medications are misleading due to packaging being labeled as a fungal treatments, parasite treatments, etc. but I will keep an eye out for that type of active ingredient.
Unfortunately, many meds over the years have not been as informative as they should have been. Case in point, certain meds work better at lower pH and some work better in higher pH. That's nowhere in the instructions on the packages. Trust me, I've complained about this for decades. Calcium and general hardness can also effect some medications. I spent over 45 years in the pet business with most of them in the tropical fish side ( fresh and salt) and spent most of that time trying to figure out why weren't working. Meds that worked in my tanks in NJ ( Yeah, I'm from there originally. :) ) weren't working in Florida. Same fish species from the same sources and no success. It wasn't until I started doing sensitivity cultures and buying my meds in bulk from pharmaceutical companies that I got to the bottom of medicating fish effectively. If you post your actual numbers, I can tell you if you were using the correct meds for your water parameters.
As for the fungal med, Expel-F from Fritz aquatics is the one I suggest these days for actual fungal infections.
And parameters have been pretty spot on as I am active with the tanks I have. I had a water sample tested as well at my local fish store.
Last, the worms you mentioned, is that something that would happen even after having them for over 2 years?? Especially for them to all go through it within the same window of time and not affect the other tank mates?
As I explained above, not all fish have them. It may have been from one farm or one country. Wholesalers get their fish from many farms in many countries. I don't know of one that is an " all in one" farm. They are specialty farms. One may do Tetras, one may do Livebearers, one Anabantids, etc. That's why wholesalers have to buy from many places to get a full stock to sell to the stores. I imported fish from all around the world. There are good sellers and there are bad ones out there. Fish quality has taken a major hit over the decades that I have been keeping fish as a hobbyist. That's just the reality of the hobby today. In your case, the fish have outward signs of multiple things which is why nobody, I assume, has been able to give you a 100% answer. I can't tell you that the reason the meds you used didn't work because you haven't given the complete parameters you used them in. Because you had deaths after some of these signs, that points to fighting more than disease because of the locations of the wounds as well as the progression of the wounds as in pics 9475, 9524 and 9529. ( I assume this is the same fish in these 3 pics. ) If it's something else, I would need your full panel of water parameters to better advise on medications if the ones you used were incorrect.
Hope this explains things better. (y)
 
Back
Top Bottom