Infection or injury

[gls90a]

I went out of town for two nights and when I came home I noticed this large dark patch on the back half of this fish. Do you think its bacterial infection, an injury, or something else?
I tested water parameters and everything comes back normal. Fish is still swimming and eating well. They are a small juvenile about 2.75 inches. 180 gallon tank.

 

[fishguy242]

hi welcome to the reef ...
how long have you had this fish? hopefully just injury ,hard to see,could you post closer /clearer pics ,how is it now?
these are all questions the experts will be looking for. best wishes.
@Jay Hemdal @vetteguy53081

 

[Suohhen]

Could be an injury, bacteria, or uronema but not likely at hopefully not. A closer clearer pic would certainly help.

 

[Jay Hemdal Verified Community Expert]

I went out of town for two nights and when I came home I noticed this large dark patch on the back half of this fish. Do you think its bacterial infection, an injury, or something else?
I tested water parameters and everything comes back normal. Fish is still swimming and eating well. They are a small juvenile about 2.75 inches. 180 gallon tank.

Is it on just the one side of the fish? Here is a link to some information that may be helpful for me to know about the issue (a video might help, as well as knowing what other fish are in the tank).

Some Helpful Hints When Posting or Responding to Threads in the Fish Disease Treatment and Diagnosis Section

Aquarium Fish Disease Problem Solving Determining the best course of action for a problem with your aquarium can be a difficult task. Even advanced aquarists will often need to seek the help of others for complicated or unique issues. Our intent here on Reef 2 Reef is to offer expert advice...

www.reef2reef.com

Jay

 

[gls90a]

Thanks for your questions and time,
Here is a video of the blue Tang. The "black spot" only appears on one side. Fish has been in display tank about 3 weeks, 2 weeks of quarantine before that. Original purchase was from Live Aquaria Divers Den. When I first put blue tang in tank, I noticed some flashing but very minor and seems to have stopped.
Tank Mates:
2 Clown Fish
1 Orange shoulder tang
1 Royal Gamma (aggressive first day, but nothing after that)
1 Pink Bar Goby
2 Red Hi Fin Goby
2 pistol shrimp
Fish only at the moment, tanking it slow and steady as I build up to mix reef. Just seeded coralline algae last week as an initial test. Lights are still off.

Tank Paramaters:
Temp 77.5 F
Salinity 35 ppt
Alk: 9.4 dkh
PH: 8.5
Phosphate: 0.13 ppm
Nitrate: ~ 2 PPM
Nitrite: not-detected
Amonia: not-detected

 

[Jay Hemdal Verified Community Expert]

The video didn't add much insight, sorry (sometimes they do). It is unlikely to be one of the primary disease issues as it it only on one side the fish - almost without exception, major disease issues are bilaterally symmetrical.

This puts us back to it being a bruise. It doesn't look to be at the surface of the skin, so at this point, I don't see a clear treatment. The fish looks o.k. otherwise, swimming well and I presume eating o.k.

Jay

 

[gls90a]

The video didn't add much insight, sorry (sometimes they do). It is unlikely to be one of the primary disease issues as it it only on one side the fish - almost without exception, major disease issues are bilaterally symmetrical.

This puts us back to it being a bruise. It doesn't look to be at the surface of the skin, so at this point, I don't see a clear treatment. The fish looks o.k. otherwise, swimming well and I presume eating o.k.

Jay

Thanks very much Jay, I appreciate your knowledge and time.

 

[Suohhen]

Def can't see much regarding the spot in the videos. The behavior of the fish however is somewhat erratic but that may just be because you are standing their filming and the clownfish swims by flashing as well. Is this typically how the fish is acting, how often do you feed and do you supplement with nori or something else?

 

[gls90a]

Def can't see much regarding the spot in the videos. The behavior of the fish however is somewhat erratic but that may just be because you are standing their filming and the clownfish swims by flashing as well. Is this typically how the fish is acting, how often do you feed and do you supplement with nori or something else?

Yes, you are correct. The fish is small so I was having to get super close to try to show the spot. Its somewhat hard to see in the video, but the tang is actually backed up into a large cave like structure it likes to hide and sleep in. The clownfish swimming by I think is mostly an optical illusion more than flashing (he is rounding the opening of the cave and leaving).

Typical feeding routine:
Morning: Flake food and Hikari Seaweed Extreme (they love this)
Lunch: Mysis
Dinner: Brine and Spirulina
Nori X2 a week so far. Though I am honestly having a hard time convincing them to even try it. Any suggestions there? I have tried moving its location on the clip and putting it near their favorite spots. They pretty much prefer and eat everything outside of Nori.

 

[Suohhen]

Clownfish aggression looks different from other fish. That snake like movement is their sign of aggression but it is very common for clowns to swim like this when outside of their territory so it is certainly not concerning. I was more so inquiring as to whether the tangs behavior has been like what is seen in the video, but yes for sure if that is its spot of territory it makes total sense for it to act that way.
Seaweed extreme is awesome stuff. It can be hard to get fish to start eating nori. The most consistent method is to have a fish that is eating it so the new fish will take interest. If none of your fish touch it then it will just simply take time. I find nori to be a bit annoying as it falls apart after a while and none of the fish care for the bigger chunks floating around. So I put in a 1/8 of a sheet at a time and I roll it up like a cigarette to keep it from tearing off in big chunks. Some chunks are nice to feed the CuC, but they don't require much. At least that is what works for me. Fresh nori from the grocery store tends to not have this issue but I find seaweed extreme to be a much easier and effective solution.

 

[gls90a]

Just wanted to bump and say thank you. The fish ended up just fine. I think it ended up being a bruise based on the way it healed. It took about a full month to clear up but fish is back to looking completely normal.