Help Please

I came down this morning to find one of my KK juvenile's lethargic, over the day it has deteriorated and developed a sore round its abdomen and it looks like the scales are loosing the colour (Very Poorly fish)

I've isolated the fish, looks like it wont last much longer.

My concern is that its been with another 5 KK fish, which are all healthy but I'm worried they will be contaminated and I would like for this not to happen.

Any advice would be gratefully appreciated.

The fish are in well established 120 litre tank with a few neons. they have been in there since 6 weeks of age and are presently approximately 4 months old, I've not done anything different other than the regular water change approximately 20% 50/50 HMA/tap water, no new plants etc.

Fed on tetra prima, quality flake, beef heart mini flake and frozen bloodworm.

Picture of the fish :- http://www.uk-angelfishforum.org.uk/gallery/Personal-album-of-Chris-Hankey/photo-2-5-pic_84.htm

Kind Regards

Chris

Sorry Chris,
Very hard to see from the photo.
If the fish have been together for many weeks, it's unlikely to be anything highly contageous.
Assuming you've checked water quality, I'd isolate the fish from the others and treat both with Esha 2000 or some other similar antibacterial treatment.
If the abdomen looks swollen then another possibility is bloat due to protozoan infection. Octozin, along with stopping feeding for a few days, and daily gravel cleans is the best treatment for that, but more to stop the infection spreading to others, usually by the time a fish bloats up it's too late to save it.

Cheers for the advice, unfortunately the fish passed away and what ever it died of seems not to have affected the other fish in the tank.

It wasn't bloat, never seen this before in any of the fish I've kept over the years. The abdomun of the fish when it passed was translutant and where you would expect the sex organ of the fish to be is where a open wound was and the fish hadn't bloated in any way? Puzzled if I'm honest, just keeping a close look on the rest of them to make sure this doesn't happen again.

Sorry to hear you lost it, hopefully it was something peculiar to that one fish, fingers crossed for you.