just lost my sailfin tang, strange symptoms

[jsrtist]

This is an established 75 gallon reef and the only fish inhabitants were a large sailfin tang and currently we have a mandarin and a pink skunk clown. The tank has been set up for a few months but was set up from two existing well aged tanks.

Water parameters always check out (no ammonia, nitrite or nitrate and pH steady at 8.2) and we have never had a problem with the fish or most of the corals. The only problem has been a temperature fluctuation over the last two days resulting in the tank ranging from 87º the other day and then down to 77º tonight. We realized one of our 250w heaters was not working.

Our sailfin was floating lifelessly at the top and we immediately thought it was due to the temperature. On closer inspection his entire body appeared emaciated and his belly had a swollen hard lump in his belly. He was fine a couple days ago, swimming, active and eating. We have had the lights off the past day and a half due to very high temperature.

My first thought is intestinal parasites–but would it happen that suddenly!? We take pictures and look at this tank constantly and usually immediately notice problems. Please help!

[andrewsmart]

most fish have some parasites.

or even velvet or ich is possible they fight these of no problem but stress caused by the temp change could weaken the fish causing it to sucumb.

not sure what killed your fish but this may help to explain it.

[Hattie B]

If you still have him you can do a necropsy; open him up and take a look inside to see if you notice and worms or anything else abnormal.

The problem is that, fish don't (generally) get really really skinny overnight. He could have had an infestation that took longer to notice then normal.

The temp problem can cause a lot of stress, but not the hard lump in his belly.

If I were you, I would open him up if you still have him to see what that hard lump was. Could even be some sort of growth..

[jsrtist]

Thanks for the replies. I have a feeling the temp did cause something as it was sudden and much too large of a swing. That was my fault.

We are planning on doing a necropsy on him tonight because I am very eager to know what the hard lump was. We wondered if he had a blockage from accidentally ingesting sand or if it was something else.

[andrewsmart]

let us know will be very interesting.

[TerryB]

My guess is that the fish got an internal vibrio bacterial infection due to the stress and subsequent suppressed immune function.

Terry B