Discus Not Adapting / White "worm" Like Growth

[adamthesim]

So, last Saturday I got my first Discus. I have placed him in my 75 gallon planted aquarium, which as far as I know has perfect water conditions.
 
> He has remained very dark in colour, but always was.
> Heavey gill and mouth breathing, but like other fish there is no attempt gasp at the surface.
> One fin is clamped, but not always. He seems to favored one fin since I got him. At first I suspected an injury when they netted him at the store. One week later and I am not so sure.
 
*** IMPORTANT***  Discus has something that looks like a wet, white string hanging from the tip his dorsal fin (the barb like fins on the top).***
- This white string appears to be growing longer and hanging off the fish like a very short leash.
 
No other fish display any signs of stress or infection.
 
Attempts to catch the Discus for inspection and possible quarantine did not go well and were abandoned. I am pretty sure the attempt nearly stressed him to death.
 
Water condition:
I have just measured (3 minutes ago) Nitrite and Nitrate: 0ppm
My ammonia: 0ppm
Temp: 80.4 F
 
 
Other Behavior:
 
>The Discus is timid, and hides a lot.
> Discus will eat but only blood worms. (frozen not freeze dried)
> Shows no interest in flakes or other meaty foods.
> Shows no aggression towards other fish and receives none.
 
Tank mates:
 
4 angels 3.5 to 4 inches
Assorted Tetra's
3 Rainbow fish
2 gourami (gold and pearl)
1 Pictus catfish (4ish inches)

 

[WILDER]

The sting hanging from his fin does it have a Y shaped tail. 
Does the stringy look like a strand of cotton or a parasite.
Can you got a pair of tweezers and nip the strand to see if it moves.

Does the strand look like this.

 

[adamthesim]

Thank you for your timely response!

 
No, the string did not appear to have a Y shaped tail. It was a simple, very white, very round looking string. It did not resemble the picture above (and gosh that looks bad!). The string has also, by the way, disappeared.

Sadly we're not out of the woods yet, Problems that remain:
 
> Fish has dark colour
> Continues to breath heavily (but not gasp at the surface)
> continues to favor one fin, keeping the other clamped most of the time.
 
Perhaps I should post a picture? Would that help?

 

[WILDER]

OK.
Does he look thin or bloated?
What does his anus look like. Does it look enlarged or red and inflamed.
Do the gills look pale with excess slime, or red and inflamed?
Any signs of flicking and rubbing?

 

[adamthesim]

Sorry for the extremely belated response, busy, busy, busy. The symptoms I was describing dissappeared over the course of  a weeks or so.
 
Yes, he would rub against objects from time to time but once the "white string" disappeared he stopped.
 
He has been behaving normally for several weeks now.
 
Thank you for the help though!

 

[WILDER]

Thank you for the update.