Chocolate tang death

[energizer28]

I bought a chocolate tang (a mimic) from the LFS 4 days ago that died unexpectantly. The fish was acclimated for about 3 hours via drip. He ate well and never showed any sign of stress. My other fish did not display any aggression towards this fish from what I could see. All other fish are doing fine. What could have happened to him? I tried a chocolate tang 3 years ago and was unsuccessful but the fish demonstrated signs of stress and did not eat. This new purchase caught me by surprise.

My 75 gallon reef tank is a little over 5 years old with the following fish:

2 ocellaris clowns
1 Royal Gramma
1 Lawnmover blennie
2 Neon gobies
5 Blue green chromis
1 Sixline wrasse
1 Green clown goby

S.G 1.022
pH 8.2

[leebca]

Sorry to hear of this loss.

Unfortunately, if the fish was larger than about 2.5 inches long, that was not a good tank for it. Like most Tangs, they need a lot of swimming space -- a 6 foot long tank as a minimum while they are young, longer as they age.

Drip method of acclimation is not the best method for marine fishes, in my opinion. I use the method that is stickied here in the Forum. The only way to tell if the water is right is by testing the water for pH and salinity (in the bag) in order to say that the bag and tank water are the same. However there is much I'm unaware of: how long was it in the bag; the water parameters in the LFS system; how long the LFS had the fish; if the fish passed the 'it's okay to acquire this fish' test; etc.

Also, I don't know the ammonia, nitrite, nitrate, alkalinity, calcium and magnesium measurements and the kind of system you have (equipment and type).

Many kinds of Tangs (like this one) just plain don't acclimate to captive life very well. They benefit by using a quarantine process to make sure they are healthy, used to humans, etc.

It's most likely the fish was harmed at time of capture, during its handling, or in your final handling. The 'harm' includes poisons, shock, acclimation concerns (not just yours, but others' too), diseases from other fishes it was exposed to during handling, etc.

If this fish brought an infectious disease into the display system, it may be too early to say it didn't. Many of those marine fish diseases can take up to a month to show themselves. Hence the recommendation for a 6-week quarantine.

At this point, only a guess is possible, but the probability is one of the above.