Ruby sharks

[Mr Grumpy]

Hi everyone, I have a community tank which has been running for several months and is well cycled, water quality is excellent and the Harlequins, Honey Gouramis and Bronze Cats in the tank are all healthy and happy. However I have introduced two Ruby Sharks (one at a time) which have both turned upside down and died within a few days. They were bought from different stockists as I thought the first one had come from a dodgy stock. Any ideas?

[Carylnz]

Did you check the pH of where they were compared to your own tank? Did you add them slowly? Was the temperature similar?
By ruby shark, do you mean Epalzeorhynchos frenatum, aka rainbow or red finned shark?
If so, these are better to be kept a single one to a tank as they are aggressive towards their own species - especially as they get older. I see you added them one at a time which I finally realised you meant you added the 2nd after the 1st died (I assume)
They need a large tank too, at least 3ft in length.

[Mr Grumpy]

Thanks for the reply Carylnz. The answer to all your points, with the exception of the PH test is yes. They were introduced properly, the tank is 3ft and you're right one was bought after the other died and from seperate suppliers. It's a mystery I haven't come across ever before, I was wondering if anyone had news of some form of disease or problem specifically affecting the species.