Black spots on yellow tang

[lmforbis]

I have had this yellow tank in QT for a couple weeks. It eats well, swims around normally, is breathing normally, no flashing, nothing to indicate anything is wrong except it has developed some bumps on his body. They were white initially and my first thought was ich. Didn't surprise me as he came out of a tank with ich and I was lowering the salinity when the spots appeared. It is now 2 weeks later and there are more bumps none have dissapeared after a few days the way ich does. Some are now brownish in color. They are bigger than ich that I have seen before, upwards of 2 mm they seem to be growing. There is also obvious swelling of the flesh in the area around the bump, kind of like a mosquito bite.
Any ideas as to what I am dealing with? Black ich (turbellaria)? How to treat it?
This is not a great pic. and it is more three dimensional than the pic shows.

 

[ThRoewer]

Black Ich, a turbellarian worm infection. Very common with fish from Hawai'i, especially the yellow tang.

Treatments include daily 10 to 15 minute freshwater dips on 5 consecutive days or
1mg/liter (1 ppm) Trichlorfon (Dylox) on 3 consecutive days or
2 g/100 liter picric acid for one hour.

Though before using Dylox or picric acid I would rather give Prazquatel (PraziPro) a try. You can always add the freshwater dips if the fish's health permits it.

 

[snorvich]

Black Ich, a turbellarian worm infection. Very common with fish from Hawai'i, especially the yellow tang.

Treatments include daily 10 to 15 minute freshwater dips on 5 consecutive days or
1mg/liter (1 ppm) Trichlorfon (Dylox) on 3 consecutive days or
2 g/100 liter picric acid for one hour.

Though before using Dylox or picric acid I would rather give Prazquatel (PraziPro) a try. You can always add the freshwater dips if the fish's health permits it.

I agree. Of additional concern, however, is the manifestation of ich earlier. Although the spots disappeared, that would be a normal part of the cryptocaryon irritans life cycle, so ich (if it was that) has not disappeared.

 

[lmforbis]

I never saw ick on this fish but I did see it on other fish in the system so I treated it as if it had ich. In your opinion can I use PraziPro during hypo salinity treatment or should I increase the salinity first.

 

[ThRoewer]

Praziquantel is also used on freshwater fish (and mammals, including humans) so I would think the salinity has no influence on the effectiveness.
More info here: Praziquantel and here: PraziPro

 

[lmforbis]

Black spots on yellow tang

Thanks. I did add the PraziPro to the hypo tank yesterday. Had to order it because my only local store Didn't carry it. When I asked the owner he had no clue what it was. Both fish in this QT tank don't seem to be having any issues with simultaneous treatments. The tank has been at 1.008 for three weeks now. In another week I will begin increasing the salinity. I usually do that over the course of 2 weeks then observe for another week. If the fish are still clean I will move them into the DT. If not we start over.

 

[Dmorty217]

Correct me if I'm wrong Steve and Roewer but if his tank is already in hypo shouldn't that kill the worms? Everything else like amphipods and bristleworms die in hypo so shouldn't the worms because of the low salinity?

 

[ThRoewer]

Correct me if I'm wrong Steve and Roewer but if his tank is already in hypo shouldn't that kill the worms? Everything else like amphipods and bristleworms die in hypo so shouldn't the worms because of the low salinity?

Worms on the outside of a fish may get killed by hyposalinity or freshwater baths, but those in the digestive tract or dug deep into the skin will likely not be affected.

 

[lmforbis]

Yesterday day I finally noticed some of the dark spots disappearing. Hopefully this is a sign that the treatment is working.