Purple Tang - Ick like spots

[Shaun Sweeney]

I have two 140 gallon tanks with a tang in each one. The tanks share a common sump. The oldest tang is probably 6 years and the youngest maybe two. I've only had the youngest for about 6 months.

The oldest fish has had ick like spots on it for at least a year but it doesn't show the typical symptom of trying to brush the spots off. It does however like hanging around one of the return outlets

The youngest (in the other tank) recently developed the spots that the older one has but no other fish, in either aquarium show any signs whatsoever.

I'm inclined to believe that I don't have ick in the tanks but I would appreciate your opinions.

Thanks ... Shaun

 

[dbl]

I'm going to move this over to the disease forum for better response. But I'm pretty sure the experts over there are going to want to see some pictures of both tangs.

 

[Shaun Sweeney]

Many thanks. I'll try and get pics asap.

 

[aykwm]

If it looks like ich and keeps returning then its possibly ich. Ich might disappear from the system for a while, probably months might pass without ich, but once a fish is stressed, the immune system of the fish is weakened and ich will pop up right back.

If the purple tang like to hang out near the return outlet then check for marine velvet or flukes. When was the last fish added to the tank? Fish breathing heavily? Sensitive to light? Cloudy eyes?

It is most probably ich that reappeared after the fish got stressed again.

 

[melypr1985]

I agree. "if it walks like a duck and quacks like a duck... then it's probably a duck"

The hanging near the return is indicative of velvet however and worries me. Pictures would help along with more detail on behavioral symptoms as listed above and last wet additions ect. Also, did you QT any of the fish in your system or the corals and inverts?

 

[Shaun Sweeney]

A bit more info:
- neither of the fish show any sign of being stressed
- the older one had to be trapped to change tanks but he had the symptoms before being trapped
- the older fish when thru a period of constantly swimming a pretty circular route but not any longer
- they both like the current which I attribute to them being active swimmers by nature
- I did QT the younger one but he has only shown the symptoms months after being added
- no cloudy eyes
- no progression in the symptoms over the year or more the older fish has had them
- no sign of any symptoms on any other fish
- both fish feed well and aggressively - particularly when it comes to their nori
- have only been able to get the roasted seaweed which all of the fish consume
- tried some proper dried seaweed the other day and everyone ignored it
- tank temp runs around 78.5 average
- parameters are closely monitored and always within acceptable range
- salinity stable at 0.25
- I have been using local ocean water - with added salt for about 9 months
- older fish had the symptoms before I switched to ocean water
- both tanks have quite a bit of current - quite a bit more than my single tank had
- lighting is primarily from 2 Radion over each tank
- lighting runs about 12 hours a day
- recently started doing the overnight micro bubble treatment which certainly improves ORP
- total system is running about 400 gallons
- I do carbon filtration and GFO
- feed (for years) has been mysis shrimp and a variety of dried foods
- neither of the fish is inclined to pose for their photograph

 

[aykwm]

Swimming in circle is due to fish being stressed from something. Fish, especially tangs like to swim in the open, never seen a healthy tang sticking to the power head or stay next to the flow. Can you describe the breathing for us, is it normal or rapid?
I believe for salinity you mean 1.025 SG.
The rest of points seem fine.

 

[4FordFamily]

I agree. "if it walks like a duck and quacks like a duck... then it's probably a duck"

The hanging near the return is indicative of velvet however and worries me. Pictures would help along with more detail on behavioral symptoms as listed above and last wet additions ect. Also, did you QT any of the fish in your system or the corals and inverts?

Yes I suspect you HAD ich and now have ich AND velvet. It's VERY common now, which is why proper qt in copper or CP is so critical.

I'd act quickly -- the treatment for ich and velvet is the same - copper or CP in a qt. All fish. Leave main tank fishless for 76 days.

 

[Shaun Sweeney]

More points:
- he hasn't done the "swim in circles" routine for some time
- what he has seems to be on the eyes as well
- catching all the fish would be quite impossible
- catching the tang would be beyond impossible
- merde!

 

[aykwm]

More points:
- he hasn't done the "swim in circles" routine for some time
- what he has seems to be on the eyes as well
- catching all the fish would be quite impossible
- catching the tang would be beyond impossible
- merde!

Ich and velvet can infect the eyes too.

If you have a fish only tank with no inverts (corals, shrimps, cleaning crew, ... then you might try dosing copper or CP in tank, although highly not recommended as copper fluctuation due to live rocks might be risky)
if you have inverts then there is no other option. There are no reef safe medication, although I tried ruby reef rally for velvet and it worked by reducing the velvet and helping the fish develop some sort of immunity, I still had marine velvet that infected any new fish added to the tank. So if you want to go this way you might lose some fish that are too late into the disease and you will not be able to add any new fish to the system. Also from what I read the immunity lasts approximately 6 months.

You can use traps to catch the fish or worst case scenario is removing the rocks and catching the fish.

 

[4FordFamily]

It's not impossible, but surely a pain. I've taken apart an entire reef tank water and rock numerous times to remove fish for treatment because I cut corners qt'ing. Never again.

Unfortunately if you don't, your fish are doomed and future additions will be as well because any lucky survivors that beat velvet (some wrasses and gobies) will pass the parasite on to fish that it will decimate

 

[Shaun Sweeney]

All bad. I guess it's time to install the trap. Are you guys saying that every fish needs to be treated even though none of the others show any symptoms?

 

[4FordFamily]

All bad. I guess it's time to install the trap. Are you guys saying that every fish needs to be treated even though none of the others show any symptoms?

Yes. By the time you trap everyone you may lose all fish. :/

 

[Humblefish]

Yes. By the time you trap everyone you may lose all fish. :/

^^ Agree

 

[Shaun Sweeney]

I guess I've been lucky because the older tang has had the disease for many months without any spread to any others.

 

[melypr1985]

I would just bite the bullet and take the rocks out to get the fish. You really do need to treat every single fish. Remove them all and leave the tank fishless for 76 days. Best of luck.

 

[4FordFamily]

I guess I've been lucky because the older tang has had the disease for many months without any spread to any others.

What kind of tang again? Some tangs can survive months but it gets worse and worse until the damage to the gills is so great they abort eating and cannot get enough oxygen so they discolor and starve.

Unfortunately this parasite will never go away if not treated with copper or CP. Even if a fish builds a resistance to it, if you ever plan to add fish to replace those that die this will repeat itself perpetually. Very very very few new fish will be able to build the resistance -- they're weak from shipping and going through the distribution system - they particularly don't stand a chance that a fat, healthy, established fish can on rare occasions.

 

[Shaun Sweeney]

How practical is it to remove all the rocks and inverts and then treat the fish "in situ"?

 

[melypr1985]

How practical is it to remove all the rocks and inverts and then treat the fish "in situ"?

Not very. If your going to go through the trouble, might as well remove the fish and treat in a tank that you don't plan on keeping inverts in again later.

 

[Shaun Sweeney]

Phooey! Thanks for all the help folks.