My Regal Tang and Chloroquine Phosphate....

Journey of a Regal Tang

Meet the newest addition to my reef tank. This Regal Tang has been through the ringer and come out the other side in a miraculous and amazing way. He went through almost 4 months of quarantine and I’ll admit that this was the most frustrating fish I’ve ever dealt with. I was sure he would die at least four times during the ordeal. Against all odds, he made it through everything, all the meds, the moves and transfers, and ended up healthy and active – if a little abused by the purple tang in my display.

Let’s start at the beginning. I work at a local fish store and manage the saltwater department. I ordered in a Regal Tang, Achilles Tang and Copperband Butterfly. As per the rules at our shop, I let the fish sit for sale for two weeks. They were kept in full therapeutic Coppersafe for the entire time and run through Prazipro twice. I purchased all three on May 27th, 2017 and brought them home. They all went into a 10-gallon QT pre-dosed with Coppersafe again at full therapeutic levels (2ppm). The Achilles Tang wouldn’t eat anything but live ghost shrimp at first and nori, the Copperband wouldn’t eat at all and the Regal was eating everything offered. Now, I obviously had ammonia issues in this small tank, so after two weeks of daily water changes I picked up a 29-gallon tank to put them in.

I did a full tank transfer and left the copper out since they were exposed to 2ppm Coppersafe for a month total. Just a few days after the transfer out of copper the Copperband developed a bacterial infection which wasn’t a huge surprise. Since the Achilles tang decided to start eating frozen during this activity, I went ahead and dosed Kanaplex, Furan2 and Metroplex into the QT for the butterfly. I ended up removing the butterfly after two days for further treatment at the shop which it didn’t survive. He was past saving when I removed him so I wasn’t expecting much. The full ten days of antibiotics was executed for the other two fish.


It's difficult to see in the pictures, but if you look closely you can see the bits of skin and slight bumps inside the circled areas. In person they looked much more pronounced and obvious. This was done with a really nice DSLR I borrowed and it was the best I could capture.

At this point the two-remaining fish have been in copper for 30 days, prazipro, and antibiotics that included metroplex. All meds were removed from the QT at the end of the antibiotic treatment and 4 days later the Regal Tang started displaying odd symptoms. His skin appeared to be almost pealing, scratching against the pvc and elevated breathing. Oddly, the Achilles Tang didn’t display any of these symptoms and both continued to eat. I was obviously worried and decided to perform a one hour Acriflavin dip using Ruby Reef Rally which reduced the symptoms to some extent post dip. Fearing velvet I started copper again but this time used cupramine for 30 more days. Oddly enough, the symptoms completely disappeared when copper was present in the water. Both fish continued to eat heartily and act completely fine during this second round of copper.

At the end of the 30 days the copper was removed from the tank with a 100% water change. It took only two days before I saw that both the Achilles tang and the Regal tang were displaying the same weird symptoms! Did I possibly cross contaminate? Mess up the dosage or testing at some point? I was very careful and this whole thing happened in another building from my display. So, here I go again with the copper and this time Metroplex is added with it. It seemed to be too much for them because on top of the original symptoms, they are both breathing very heavily and laying on the bottom of the tank sort of flopping around or swimming in tight strange circles. Neither would eat or do anything else but scare the heck out of me. Their color was extremely faded, and now I’m scared. Another 100% water change and carbon to pull everything out of the tank.

Boy, I just can’t tell you how frustrated I was at this point. Poor Humblefish had to listen to it all and being the super nice guy that he is, lent me an ear and some suggestions all during this process. We are both suspecting copper-resistant velvet or possibly a very persistent strain of Brook since the metroplex and rally baths didn’t do anything to cure it. This is a really scary thought and since one is a Regal tang, Chloroquine Phosphate seems not doable at all since anecdotal evidence points to them not being compatible. Despite the obvious risks, I decided that I had nothing to lose at this point and neither did the fish. They would die without the CP anyway, so I ordered some and paid the extra freight for 2 day shipping in hopes of saving them both. There was a typo on the shipping address so the CP was delayed for an extra week. In that time the Achilles tang perked up some after the meds were removed from the tank. He swam around a bit and wasn’t breathing heavily, but still didn’t eat. He lasted just a couple days before he died. The Regal tang stayed on the floor of the tank or nose down next to the filter breathing heavily and looking like he was on death’s doorstep for 5 days. The last two days before the CP arrived he perked up quite a bit and started eating again. The skin condition was still present and he still scratched on the pvc, but it was an improvement.

I recieved the CP on August 6th, set the 10 gallon tank back up and did a full tank transfer with all new equipment, water, and pre-seeded filter sponge. I dosed the CP in the tank at 60mg per gallon and planned to run this for 30 days. I did only one water change during this time adding the appropriate amount of CP to equal the 60mg per gallon. After two weeks in the CP the Regal tang stopped eating Nori completely. He still had an excellent appetite for LRS fish frenzy and frozen mysis so I continued to feed it every day, once a day to be sure the water quality didn’t suffer. After three weeks in the CP all symptoms had gone from his behavior and appearance. I did find a bit of “patchiness” on his side but it didn’t look like the “pealing” from before. Being torn between something truly being wrong with him still or it just being exposure to the CP, I purchased a freshwater black molly as a canary fish.

The CP was removed from the QT completely on September 7th with large water changes and carbon. The freshwater molly was introduced to the tank with the tang and the clock starts on the two-week observation period. Unfortunately, I didn’t take too much care with acclimation so the molly died two days later of osmotic shock. The good news is the molly showed no signs of disease when it died and the patchiness observed earlier on the tang had gone away. The Regal had also eaten ¼ sheet of nori for the first time in several weeks! He continued to eat nori and frozen foods for the entire observation period and never displayed any worrisome symptoms in that time.

After nearly 4 months of QT and thinking certain death was on the horizon for him several times, he finally made it to the display on September 17th. He’s a little skinny from not eating the nori for so many weeks, but is now getting fed Frozen and Nori as much as possible to really pack the weight on. The Purple tang didn’t take too kindly to the Regal and went from murderous to dislike after several days together. You’ll see several scratches and cuts on the Regal, but rest assured he stood up for himself and the Purple has a few too.

As far as myself or Humblefish know, this is the first time a Regal Tang has made it all the way through a 30-day CP treatment. Every single other attempt has ended with the Regal dying before the treatment ended. It’s not exactly understood why this happens. I wrote this story down to show exactly what I did with this fish in hopes that others that have made the attempt will chime in with what I may have done differently than they did. We should try to figure out if this was a “fluke”, an oddity singular to this one individual Regal tang or something special that I did to make the treatment successful for him that others can repeat.

*All photos and videos were done by myself*
About author
Meredith Presley started keeping marine aquariums in 2007. She’s done everything wrong that can be done in the hobby (mostly but not all in that first year) and that has afforded her to learn a lot of hard lessons. Recently she’s been focused on marine disease diagnosis and treatment and hopes to focus on breeding soon as well. She also keeps a blog with basic info on saltwater keeping and her experiences with her own tank and livestock.

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