Reptile & Amphibian Forums

I have two Ryukin Goldfish that I've had for about 4 years. The larger one has an area (see pictures) that has something wrong with it. I'm not sure if it is an injury or some sort of disease or parasite or?? I'm worried that it is something that is spreading because he has started getting a much smaller area on his other side. The bad area first showed up a few weeks ago and I thought he had just rubbed himself on something. I thought it was getting better, but now it looks worse. The two fish live alone in a 30 gallon aquarium with a Penguin 170 Bio-Wheel filter. I do a water change (20%) every other week and change the filter once a month. They eat a variety of goldfish food (Bio-Blend sinking pellets, TetraFin Goldfish Crisps) as well as algae wafers and some frozen worms, veggie blends and shrimp. The fish acts perfectly normal and eats like a pig.

The pictures and more information are up on a website so you can just go look at it all in one place.

http://quantum.uark.edu/Chartwell/goldfish.htm

Any advice would be appreciated!

Susan Campbell
mailto:chartwell@quantum.uark.edu
Goldfish

it could be carp pox but i'm not 100% sure. if you could tell me more about the set up you have then that may point the finger to what your fish may have.
how many gallons and how many fish are in the tank?
any new additions before the marks appeared?
what is the temperature of the tank?
you have said you do a water change every couple of weeks. this may not be enough to keep the water clean.
have you any test kits for ammonia, nitrite, nitrate and ph?
if not then you can get some water tested at your lfs and ask them to write the results down.
when you do water changes do you do a gravel vac as well. this is really important for your fish.
the filter needs to turn over the water 10 times every hour for it to be effective.
the good news is that if it is carp pox then it will clear up with good tank maintenance and more regular cleaning of the tank.
you have also said that you change the media in the filter each month. is this the sponge that you are throwing away? i am not from the u.s so i am unfamiliar with the filter you have. if you are throwing away the sponge then you are getting rid of all the good bugs in the filter which eat up ammonia and nitrite. sponges should be rinsed each week in used tank water and then replaced back in the filter.

thats a lot of questions i have asked and i apologise if you already are aware of most of it but i like to get the whole picture where possible.
in the meantime do a 50% water change twice a week and use a gravel vac at the same time. dechlorinate all water going back in and i hope the pox (if that is what it is) will clear up. and please try to get those water tests done. thank you and hope to hear from you soon.