Goldfish tail...bubble

[shayfish]

I have a fancy goldfish with, well a... a bubble. It's right at the "fork" of his tailfin on the underside. I noticed a little something funny looking on the outside, which you can sort of see in this pic along the top of the tailfin. Underneath there is a tiny bubble which he wouldn't let me get a shot of.



What the heck is going on here? I've never heard of this before.

[Devilishturtles]

Perhaps just one of those benign growths that occur. Assuming the fish is still swimming, eating, cavorting about, I wouldn't worry.

Do you keep your tank cold? I have found that keeping goldies at tropical temps causes VERY weird things to happen to them.

[shayfish]

Tank temp is 74. Could that really be it? It is a very strange sight when you get a look at it.

[Zagz]

74 is ok for a fancy goldy. I wouldn't go any higher in the temps though. I agree with DT, most likely a natural occurance. Only way to be sure is to keep an eye on the fish and behaviours of the fish.

[jsoong]

If the fish behaviour is normal, then it is likely something fairly benign.

A blister like lesion is probably some kind of Pox (carp Pox?), or may be early lymphocystis. Both are viral infections & usually self limiting. This is from the Merck Manual:
http://www.merckvetmanual.com/mvm/in.../bc/170416.htm

Disagree with the comment on temp. Fancy golds prefers the temp in the mid to high 70's. Breeder routinely keep them in low 80's to improve growth. Although single tailed golds prefer cooler water, they do well in summer when the temp hit 80 or even 90 (water temp will be less, since you should be providing some shade in the pond).

If the lesion is actually lymphocystis, keeping the golds in warmer water may help eradicate the virus. This comes from observations that the lesions often disappear in the heat of summer. At any rate, upping my tank temp to 78 (for about a month) appeared to have cured one of my golds of it.

[Devilishturtles]

Thanks for the correction, jsoong. I had two fancy golds that I tried keeping in my tropical tank and they continually had bad things happening to them. Weird things that nobody could explain. I attributed it to the higher temps.

[Zagz]

I had similar problems with my goldies if the temps were above 75. Same with my stepmom. Goes to show that sometimes you have to base it on the individual fish. Although there are several varying view on the internet about the ideal temps for fancy goldfish. It can be quite confusing when doing research.

This site recommends 19C or 66 F.

This site recommends 68-72F.

This site recommends 40-80F/

[shayfish]

Okay, thanks for the info. I will keep watch for unusual behaviour and perhaps I will up the temp slowly to 78 or so and see if that does it.

[jsoong]

Originally Posted by Zagz

I had similar problems with my goldies if the temps were above 75. Same with my stepmom. Goes to show that sometimes you have to base it on the individual fish. ......

I think it has to do with the individual tank as well .... Golds need a lot of O2, and cooler water carries more of it. Upping the water temp will require a corresponding increase in water movement to compensate. If one has a small tank with little surface area & slow water circulation, the O2 level could drop to dangerously low levels for the golds.

[Zagz]

I run 3 bubblers in my goldie tank. LOL they were fighting to play in the bubbles so I had no choice. Opinionated fish

[DepotFish]

Blisters are common in the split between the tail. It has nothing to do with temperature and more to do with water quality. 74-78 is fine for goldfish.

[MommaDee]

I need to know is your fish okay now? I have the same problem and my 4yr old son is very concerned about Kelly. Kelly has only been with us for about 6 months.. she is Mr. Fish's friend He has been with us for 4yrs. help please respond...

[dkpate]

Momma, you should make a new post in the unhealthy section, since this thread is 4 years old.