Naso Tang black spot

Hello,

Quick Question, I have a large Naso tang that just today developed this strange black patern of dots on his face, and i'm wondering if I should be concerned

Tank specs are: 150g , 77 degres , amonia - 0 , nitrite - 0 , nitrate - 0 , ph 8.2ish , SG 1.022... Livestock: Naso 8 - 10" , Yellow 4" , Maroon clown 2" cleaner wrasse. 

Any suggestions?  Garlic?  Any ideas what it is...  He is eating like the sea cow he is so kinda wierd..

thanks

dan

To me, your salinity looks a little low.  At 77 degrees and with a specific gravity of 1.022, your ppt of salt is ~31.2.  Normal sea water varies from place to place, but is generally at about 35 - 38 ppt.  If you were to keep your temp at 77 degrees, you would need a specific gravity between 1.025 (35 ppt), and 1.027 (37.8 ppt) to achieve that.  From what I have read, fish can survive in other conditions, but will feel it in the long run. 

Here is a link on water temp. and salinity: http://www.animalnetwork.com/fish2/aqfm/1997/nov/features/1/default.asp

Dr. Shimek has done a great deal of research on the subject.

I am sure that diet and other stresses may play a part in what your fish is experiencing, but water quality may be where you would like to start.

Just my opinion - Jared.

Arjen et al,

Don't forget that we aren't trying to replicate nature.  We are trying to do better.  Yes 83 or 84 degrees is very common.  But try keeping xenia at that temp, never happen.  Also, we aren't only dealing with coral, but fishes.  Lower the temp the better for fishes.  And the lower salinity the better as well.  So.... I say do whatever works for you.  Which for me is 76-78 degrees, with 1.023sg. 

Adam

Dan,

First I want to know how you included the photo in your post!!  I have tried but have not been able to do that.

?How long have you had the fish?

?Have you adjusted anything or changed anything in the tank recently? In your next post, please include a photo of the interior of the tank so we can see the environment it is living in.

Without knowing any of the above, my first opinion is that it is either a temporary condition that will go away if the Tang is in a good environment or that it is an ordinary skin blemish.

I've had Yellow Tangs with dark brown splotches on their face and they were fine. On one of them it didn't go away for months so don't worry.

It's definitely not your temp or salinity. Those are fine. You guys are worrying too much about those parameters. What Ron's study tells me is that significant fluctuations occur so we need not worry so much about those levels. A fluctuation of 10% is no big deal even when almost immediate like dumping an organism into another tank without any acclimation.

FYI I never throw a fish into colder water but you can throw it into 10% warmer water without worry. Coral doesn't care. (ph is another matter though)

Regarding temp, we need to ask what happens when the temperature goes up. Metabolism goes up and dissolved oxygen goes down. This is why we keep our tanks at 75 - 80 degrees. We don't want the organisms to respirate too fast in an oxygen poor environment! That's unhealthy.

Mark

I had to upload the picture to my website on my ISP (xmission.com) and then I used the image button that looks like a little tree in the tool button list next to the smiley and put the URL to the pic including the .jpg extension in and it just magically shows up..         I have some space on my site if anyone wants me to post them a pic it's no prob..

Thanks

Dan