Why the end of the gill get black?

[wo]

Hi,

I find the end of the gill of some discus turn black. Why is it? Is this some sympton of fluke. Are there any picture of fluke posted on web? One of my BD once was all blue but one day he bumped himself to the heater and some of his scales fell.There were never any wound but even today the 1cm large black dot could be easily seen. Is it normal?

Today I find my tank with some thread worm. (1cm long transparent) I try to kill them with formalin so I put 60 ml of formalin for 100 gallon tank. But most of them don't die, why? I know maybe they are harmless but they really grow in large numbers; it become kind of scary to look at. I did not do WC because I was in middle of hole-in-the-head treatment for one fish for 8 days. Ususally I do daily 50%WC. How could I kill those thread worms?

What is the precaution you use when you use formalin bath for discus? It could cause cancer if it touch the human skin. What about for the fish?

Could any one help me. Thanks a lot!

[Ardan]

Hi,
use good ventilation with formalin,
keep off skin
make sure it is not expired


The thread like worms may be planaria (if they crawl and don't swim)
to get rid of them, cleaning of tank and inside glass and removing all uneaten food helps. Wc every day will help keep the organics out of the water (this is food for the worms)

The black dot could be an injury or nerve damage. Nothing can be done for this, sometimes it disappears on its own.

The black dot could be decaying cells if an infection were present, If it got worse I would consider an antibiotic.


You could move the fish to clean water in a hospital tank to help get rid of worms. When treating for hole in the head, clean water is paramount anyway.

hth
Ardan :sun:

[wo]

Hi Steelhead:

Thanks for your detailed explanation that really helps.