dieseldoctorx

Hi all,

I'm new posting here, although I've used the site for research purposes previously, and it is very helpful.
I have a question regarding a new red tail shark (about 2 inches in length) I purchased and introduced to my 29 gallon cycled aquarium (all parameters are perfect, except that iron levels are a little high). For the first 5 days after purchase, the shark was absolutely fine---showing an appetite, growing more colorful, staking out a territory, etc. However, I woke up this morning to find it swimming near the top of the tank, often on its side, in a very strange way.
It appears to have energy enough, i.e. it is not just floating or letting the current take it, but it is swimming in a decidedly abnormal manner. I also noticed that the edges of its fins seemed a little frayed, which I think I would have noticed before. Why it is staying at the surface is perplexing to me, as the tank has a powerful filter that gives the tank lots of surface agitation and aeration, and I run a whisper 40 air pump at night to increase nighttime oxygenation for the plants (light CO2 bubbling during the day).
My only hypothesis as to the cause of this behavior regards the fish's only other tankmate, a ~7 inch pleco. Is it probable (I know it's possible) that my pleco would view the little shark as a food source? I feed the pleco algae wafers as well as hair algae I pick out of my other tank, cucumber slices, and lettuce, so I don't think it's underfed. Should I move the shark to isolation in a 10g quarantine tank? Or should I be worrying about possible disease? The shark's coloration still looks good . . .
Thanks for your help, and sorry about the length of the post---I just wanted to get all the info out on the table.

sirdarksol

Welcome to Fishlore. I

Ugh, if it's on it's side, it sounds like swim bladder disease. I don't know a lot about this particular illness. Hopefully one of the members who are more experienced with treating illness will come along pretty soon here.

And don't worry about length of post, it's better for us to have all of the info.
Speaking of which, you say that parameters are perfect, and your Aquarium Info says that Ammonia is 0, Nitrite is 0, and Nitrate is around 5, are these numbers correct? (I only ask because we get a lot of people who say "my water is perfect" and then we find out that they have ammonia and nitrite. It's just become a really good idea to verify everything before we go into a discussion of possible problems)

Good luck with everything and if you have any other questions, please feel free to post them.

dieseldoctorx

Thanks for the reply. Unfortunately, the red tail passed on this afternoon.

As for the nitrite and ammonia levels, they have been fine for some time . . . I seeded the tank with bacteria from an established tank, and I test them every week, so I know they're OK.

I did some more research on the forum and found a post regarding chemical poisoning of a member's fish (because as I mentioned, the iron levels were high), and the symptoms they described in the post were identical to the ones my red tail was exhibiting (sideways swimming near the surface, seeming difficulty to swim downwards, etc.). While I know it would take high concentrations for said poisoning to occur, they were in the range of 0.8ppm, which is pretty high . . . I just thought it would be OK because the pleco has been in the tank longer and is fine. I guess that is because it is a hardier and larger fish.

Iron poisoning would also explain why it took a matter of days for the symptoms to manifest themselves--the element had to biologically accumulate in the fish for a time. It also, unfortunately, would explain why moving it to a quarantine tank ultimately did no good, as it was too late.

I thought about the swim bladder too, but its stomach wasn't at all swollen, and I'm not sure if it would die so suddenly from a swim bladder infection.

I since have done a massive water change of ~50% in the tank and gotten the iron down to almost 0ppm for the time. I exchanged the poor fish for a new red tail, and it is quite happily acclimating to the new tank now. I wish I could have known this before, but this hobby has a steep learning curve.