Help identify disease

Question
I bought a well established reef tank with six fish and a pencil urchin a year ago. This is my first salt water tank and have had absolutely no problems in the tank. All my levels are great!! But, within the last week and a half, I have lost all but two of my fish, which seem to be soon to go as well. I have lost a domino damsel, clown fish, blue/yellow tail damsel, and a dottyback. The two remaining fish are a blue chromis (spelling)? and a black fish with vibrant blue stripes. The fish would get a milky coating all over, that looked like it was peeling off before they would die. The black fish that is left, looks to have milky eyes and has lost some color. The fish have quit eating about three days before death as well. I never seen anyone of them scratching on rocks, but they would breath a little heavier. The light blue chromis that is left, seems to be unaffected, or I can't tell because it is so light in color. My 46 gal tank has crushed coral for base and live rock. I have been treating the tank with an organic disease treatment called ich attack by Kordon. It came recommended so I could use it with the urchin in the tank. My questions are; what does this disease sound like, why did I get it when I have not introduced any new tank mates, and since I am sure the fish will all die, will the urchin be fine. Also, once everyone has died, how long do I need to let the tank run free of fish before I can put new ones in?

Answer
Hi Mandy,

Regarding the description you gave, "milky coating all over, that looked like it was peeling off before they would die". It sounds like a virus, however without actually seeing the fish, it would be hard to pinpoint an exact illness.

However from your description it may be Lymphocyctis virus.

This virus induces massive cells to form which appear grossly as grayish-white masses on the fins and gills. Such abnormal cells may also be found in the muscle and body cavity.

See this link for more information on this fish virus http://www.vet.uga.edu/vpp/clerk/Kurkjian/

Regarding your sea urchin, it may survive being an invertebrate; this virus will have different effects on fish versus invertebrates.

Regarding a minimum to wait:

I would wait at least a month before introducing new life to the tank once again.

Good Luck with all your saltwater fish endeavors!

Regards,
Dave

All Experts - Volunteer Expert

http://www.ocreef.com - Director