Scales are gone...

[FireZeus]

Scales are gone...(pic included)

55gl tank
Occupants: 2 med oscars, 1 small oscar, and 3 large comets (7")

Problem: All 3 comets (glorified goldfish) have some sort of decay going on. One has the scales and any protective skin missing from over 50% of his body. You can see the redness of the meat, even what appears to be the fatty layers between it. The others have bumps, or discoloration, and what looks like boils. The oscars have no signs of anything going wrong with them. This started with the comets some time ago, but now upon returning from vacation, it looks miserable, but they act fine. What is it?? Cancer, or old age, or is there a disease? What aren't the oscars being affected? I have had them in the same tank for over 6 months and have never seen the oscars attack anything more than a hotdog or feeder fish.

 

[Kit Walker]

I'm not sure if your new to this game...but oscars are carnivourous cichlids that eat fish such as goldfish. The damage looks like the oscars have had a go at trying to take a bite of your goldfish. Even if you don't catch them in the act, they could be preying when the lights are out. I'd isolate the goldfish and treat with Melafix. The red exposed flesh would be very susceptible to bacteria. Either that or leave them for the oscars to finish off.

Also, 3 oscars in a 55G is really really pushing it. A decent large oscar commands a minimum 75G for one specimen. Even with a pair in 55G, it is a battle to keep wastes under control plus nitrates.

Good luck.

 

[FireZeus]

No, I've been here a while now but my post count doesn' reflect that due to re-registering. However, why would the oscars attack now, after all this time? If this is the case, the only reason I can come up with is that they are gaining size on the comets and trying to eat them.
One last thing, how big are these oscars going to get?

 

[Richer]

Oscars getting larger than a foot in length are not unheard of. A 55 gallon is limiting because it only has a width of 12inches (for most 55 gallons). This barely gives an fully grown oscar enough room to turn around. Thats why a 75 gallon or larger is suggested for _one_ oscar. I wouldn't be surprised if the oscar were trying to eat your goldfish. I'd suspect with the oscar growing up, its starting to see the goldfish as a potential food source.
Kit Walker is right... you are really pushing that tank. When your goldfish are killed, the oscars will turn on themselves. Within a few months, don't be surprised if you are left with one oscar.. or 3 badly beaten up ones. I would see if you can return your two oscars and get another tank for your goldfish. Goldfish are temperate water fish, and don't do as well in warmer conditions. I would recommend another at least 55 gallon (larger if you can) for your 3 comets.
Till then, isolate your injured comets (via tank divider, hospital tank, etc.) and treat them with melafix.

HTH
-Richer

 

[FireZeus]

Thanks for the replies guys. I like the "Doc, can I have a second opinion" approach. I have quite a bit of time before the oscars get to that size, they are currently about 5 and 2 inches. The hospital tank is being set up and will monitor them. Thanks again.

 

[wetmanNY]

www.fishdoc.co.uk and www.koivet.net and www.fish-disease.com may have some help on this specifically koi/goldfish problem.

Goldfish and Oscars rarely thrive together over the long run.

 

[FireZeus]

I have the golds in my other tank. They seem to be recovering well. The oscars probably like the change.

 

[wetmanNY]

C'mon, Firezeus, you have to tell what your treatment is. Especially if it's turning out successful. Why do you think we're hanging out here?... to find out stuff!