Leebca, you helped me before

[leebca]

You're using BOTH Maracyn One and Two for Saltwater fish? or are you just using One now? I know you've used Two before. Are you now using One? How long have you been using One?

Is the fish still perky? or would you describe the fish as listless?

Are the fins that are split have any unclear area? any part of the fin(s) that are cloudy?

You have used Maracyn Two for more than 5 days. True? If you have also used Maracyn One for more than 3 days, and there is no improvement, then it is time to switch antibiotics.

I wish I could have a scraping of your fish to look at to try and identify the microbe we might be dealing with. Each microbe has its most worse enemy in an antibiotic -- that is -- not all antibiotics will equally be effective on the microbe. Identification of the bacteria by microscope would tell what the optimal antibiotic should be used.

If you have tried Maracyn One and it's been more than 3 days without results, switch to Tetracycline formulated for saltwater fish. This antibiotic is particularly effective against two groups of bacteria.

Some suggested medications that contain the above Tetracycline for saltwater fish:
Aquarium Products Gel-Tek Tetracycline (best because it is fed to the fish)
Eaton's Aquaticure Tetracycline

To save time, obtain the product Spectrogram. It's a combination of two other antibiotics and should Tetracycline not work, the next to try is Spectrogram.

The above antibiotics and antibiotic combinations reach out and kill a variety of less common bacteria.

Still answer my questions, please. We'll find the right medication for those bacteria!

How are the other fish in your aquarium doing? Make sure the QT water is perfect in quality.

[r0bin]

I very much appreciate your help. Marlin is gone. I cried all night.

[r0bin]

ps The fish in my main tank, clarkii clown, purple psuedo, and bi-color blennie all are fine. I asume this was nothing contagious. Should I be concerned about adding new fish to my tank, or is this something just marlin had?

[r0bin]

Also to help me understand what happened to marlin, here a description if what it looked like. His fin deteriated greatly. It was like a hole and it was cloudy looking, almost cottony. As the hole got biggger it worked its was towards his body. Then the part of the fin that was split would look bloody at times and then that part would deteriate. It just keep doing all this and would get larger and larger and cover more area. It looked black, yet cloudy and bloody. Thats about the best I can do on description.

[leebca]

Very sorry for your loss.

I'd let the tank hold off for any new additions for about a month total from when Marlin was put into the QT.

The symptoms you describe are that of a bacterial infection. The important word you used was 'cottony.' When an affected area has cottony growth on it, it is sometimes a symptom of a fungal attack. Fungus in marine ornamentals is very rare (and usually pretty obvious).

But, this is all 'arm-chair' diagnosis. An hour with the fish and microscope and it would likely be much better diagnosed.

Watch your other fish closely. If it was a bacterial type problem, your other fish should be okay as long as they are being nourished properly in good quality water. Fungal infections are very contagious, so it would not be uncommon if the fish had a fungal infection for it to spread to one or another fish.

Since Marlin was in the main tank for so long, I doubt you'll see any signs of a fungal infection, since it should have easily spread from Marlin during its initial symptoms.