Fin rot, what is it and what to do

MiniBukta · Nov 15, 2020

Need help diagnosing my chromis. Just saw this yesterday, and it’s only affecting two chromis. Water parameters are all in range, I recently dropped food down a bit to help control hair algae problems I’ve been having, that’s the only change. No other fish seem to have any issues.

The fins of the two chromis affected are tattered, and the fin of one fish has some almost reddish looking algae sort of color to it in spots. It is also swimming at the top of the water, which isn’t normal.

Any help would be greatly appreciated, I’ve had these little guys for years.

vetteguy53081 · Nov 15, 2020

What you are describing appears to be uronema(common with chromis)
Start with a freshwater dip for relief . Metro can be added to food if they’re still eating.

Treatment of choice is a 45 minute formalin bath (using Quick Cure), followed by transfer into a new/sterile QT. Once in QT, it is very important to do followup treatment to assure all of the parasites have been eliminated. This can be accomplished by dosing and food soaking metronidazole ( Seachem Metroplex) for 10-14 days.

Jay Hemdal · Nov 16, 2020

While Chromis are notorious for developing Uronema, that almost only is seen in newly acquired ones. Both fish have fin damage from another fish, the dynamics of damselfish in captivity can change over time, so my guess they are fighting (hanging at the surface can be a symptom of this as well). I can't see the reddish color that you mention....Is one damsel unaffected with good fins? That would be your culprit. If all of the damsels are affected, then either another fish in the tank is causing this, or I'm wrong (grin).

Jay

MiniBukta · Nov 16, 2020

Jay Hemdal said:
While Chromis are notorious for developing Uronema, that almost only is seen in newly acquired ones. Both fish have fin damage from another fish, the dynamics of damselfish in captivity can change over time, so my guess they are fighting (hanging at the surface can be a symptom of this as well). I can't see the reddish color that you mention....Is one damsel unaffected with good fins? That would be your culprit. If all of the damsels are affected, then either another fish in the tank is causing this, or I'm wrong (grin).

Jay

One of the two chromis affected has its rear fin almost completely gone this morning, and what’s not gone is a rust/red color. Looks like the color of that red carpet algae, cyano I think. The other doesn’t have that, just tattered fins.
I see no obvious aggression other than the normal hey this is my spot. But nothing that would lead me to believe it’s another fish.

MiniBukta · Nov 16, 2020

Got some better pics, this is the one of the two that isn’t looking very good right now. I want to save the fish if possible, but most importantly protect my other fish from similar. Also a picture of the only other fish with tattered fins.

Jay Hemdal · Nov 16, 2020

Fin rot on the caudal is always caused by some initial damage...fighting, breeding, rubbing against something. Fin rot on all fins could be caused by a general bacterial infection, but I really don’t see that very often.
Remember; fish fighting can happen in a split second, and while you are watching the fish, they are busy watching you!
I think you need to isolate both damsels from one another, in a treatment tank and dose them with a broad spectrum gram negative antibiotic. If you go that route, let me know and I can suggest some doses.
Jay

MiniBukta · Nov 16, 2020

Jay Hemdal said:
Fin rot on the caudal is always caused by some initial damage...fighting, breeding, rubbing against something. Fin rot on all fins could be caused by a general bacterial infection, but I really don’t see that very often.
Remember; fish fighting can happen in a split second, and while you are watching the fish, they are busy watching you!
I think you need to isolate both damsels from one another, in a treatment tank and dose them with a broad spectrum gram negative antibiotic. If you go that route, let me know and I can suggest some doses.
Jay

Thank you for your reply! I will be putting them in a QT tonight after work and medicating. Not sure what route to do exactly, very new to this.
From what I’m seeing, I’ve got metroplex and Paraguard coming to treat over a couple weeks.

MiniBukta · Nov 16, 2020

Jay Hemdal said:
Fin rot on the caudal is always caused by some initial damage...fighting, breeding, rubbing against something. Fin rot on all fins could be caused by a general bacterial infection, but I really don’t see that very often.
Remember; fish fighting can happen in a split second, and while you are watching the fish, they are busy watching you!
I think you need to isolate both damsels from one another, in a treatment tank and dose them with a broad spectrum gram negative antibiotic. If you go that route, let me know and I can suggest some doses.
Jay

I ordered some rally pro ruby sea, and I have a tank I can separate the two fish in for QT. So that is my current plan.

Jay Hemdal · Nov 16, 2020

Well, that wouldn't be my first choice - it has acriflavine that will help somewhat, but it also has formalin that really won't help this issue. Be sure not to dose the Paraguard and Ruby Reef at the same time, they overlap some in terms of formalin derived ingredients.

Jay