Pond Boss Forums GENERAL QUESTIONS Help Bluegill -Disease

I have juvenile bluegills in my indoor tanks (~4 inch size, 25-30g; Density: 300 / 1000 L). I stocked them a month ago. Initially I observed few mortalities, but then (after a week) mortality was stopped for few days. Later, I started seeing mortality again. But, it was less and I did not see any serious disease symptoms (expcept caudal fin erosion in few of them). All of a sudden, I saw 5 bluegills dying every day from each tank - I noticed red color in the caudal peduncle area and also, area from belly to caudal peduncle.When I cut open those area, I could see reddish muscle. In some fish I don't see such symtoms. other common symptoms include fish become dark a day before dying, and reduced swimming, don't eat feed.

I tried follwing treatments:
1st: Oxytetracycline - for 3 days. (did not see any serious improvement) totally about 400 g (i need to recheck for the exact dose)
2nd: salt treatment - 2 ppt for 2 dats(i read (by google search) that nitrifying bacteria can tolerate up to 6 ppt) - no much improvement
3rd: Melafix - it is a herbal product - extracted from teaplant. It is recommended to treat ulcer, open wound, fin/tail rot, etc (http://www.pondliner.com/MelaFix.htm)
treated for 4 days.

I wash my filer for every 2 days, and do 30-40% of water exchange almost every day. But I still see some mortality (at least 1-2 fish a day in each tank).

I am open to any suggestions.

Thanks

Karthik,

Given that the oxytetracycline did not show any appreciable results, perhaps the culprit for the infection is not a bacterium. It could very well be a protozoan parasite (Trichodina, Epistylus, etc.). If this is the case, a typical treament regime involves using formalin at low doses. I would encourage you to research the dosages needed as I don't have them memorized. Hope this helps.

How about reducing the densites? They seem kind of high to me.

Hi Memebers,
I tried Copper safe. Also, now the density has been almost reduced to 200 per 1000L. I sprinkled some formalin this morning, but it may not be sufficient to kill bacteria or parasite, since I applied only little (~80 ml of 10% formalin in 2000 L water!!!).

They keep dying. I'm going crazy!

I don't know much about aquariums but wouldn't the copper or the formalin wreak havoc with the beneficial bacteria in your filter? Even if it doesn't when you say "sprinkle" are you measuring out a precise amount or guessing? Remember many therapeutic drugs are just under the threshold to kill the patient.