Black mark on semilarvatus tail area

puffy127 · Apr 13, 2018

Got this semilarvatus butterflyfish about a week ago and it had these black markings on both sides of the body, near the tail area. Retailer tells me it's nothing to worry about and that it's probably just stress markings since it's kind of symmetrical on both sides. It's been a little over a week now and they are still there. Is this something I should be concerned about?

Humblefish · Apr 13, 2018

I've never seen markings like that on a C. semilarvatus. Would treat with Kanaplex, the same as you are doing for the Goldflake. However, you may need to add-in Furan-2 & Metroplex if Kanaplex doesn't clear this up.

FarmerTy · Apr 13, 2018

Humblefish said:
I've never seen markings like that on a C. semilarvatus. Would treat with Kanaplex, the same as you are doing for the Goldflake. However, you may need to add-in Furan-2 & Metroplex if Kanaplex doesn't clear this up.

I'm not an expect on the golden butterfly but the one I QTed for a month and sold had the same black markings on the tail area. It might just not be anything but monitor and treat as Humblefish if it seems like its not natural markings and is spreading.

Here's my classifieds ad for the fish I sold with the markings... You can see it in the video too.

https://www.reef2reef.com/threads/red-sea-golden-butterflyfish.349844/

puffy127 · May 7, 2018

Well, the kanaplex did not clear it up, but based on the post by @FarmerTy , I'm not sure it was actually an infection. Anyhow, he made it through TTM (36 hour transfers) and 2 doses of prazi. He's been in a larger cycled QT for 3 weeks now, but after 1 week of normal behavior, he all of a sudden became shy, hiding in the back corner or in the pvc fittings for the past 2 weeks. He never displayed this behavior during TTM. He still eats great and no visible signs of parasites. I did a fw dip on him as well and no visible flukes. I'm not sure what to do at this point. I'm hesistant to put him into the DT, but nothing seems to be changing in the QT.

puffy127 · May 7, 2018

Here is how he is most of the day - hiding in the pvc fitting, even at a funny angle:

Here he is at feeding, perfectly normal:

Humblefish · May 7, 2018

Is the spot spreading or getting worse? Or pretty much staying the same??

puffy127 · May 7, 2018

Spot is pretty much the same.

Humblefish · May 7, 2018

puffy127 said:
Spot is pretty much the same.

@FarmerTy is probably right then; it's just a natural marking. If it were an infection, it would grow, shrink, change in some way. Sorry for the misdiagnosis.

puffy127 · May 8, 2018

No worries at all. I appreciate all the help. Should I be worried about his change in behavior? Or should I go ahead and transfer him to the DT?

Humblefish · May 8, 2018

puffy127 said:
No worries at all. I appreciate all the help. Should I be worried about his change in behavior? Or should I go ahead and transfer him to the DT?

I'd put him back in the DT. The change in behavior could just be not liking QT.

puffy127 · May 8, 2018

Humblefish said:
I'd put him back in the DT. The change in behavior could just be not liking QT.

Thanks for all the help!

lagatbezan · May 8, 2018

They are tad sensitive with having pristine water conditions. I had a butterfly fish that would do that when the conditions in the qt were not perfect. A large water change usually resolved it. Congrats on a beautiful fish!