75 Gallon Tank Possible Black Cotton mouth?

[Sb092]

I have 3 jumbo swordtails. One looked as if he has a broken jaw when I first got him. One side of his lips/mouth drooped. I just noticed his mouth is black. I am not sure if fish bruise or not?
Other than the discoloration on his mouth, he is doing fine. Eats, swims, and stays away from the other two swordtails (who like to fight). I have tried to get photos… these are the best could do.

Fish tank parameters are fine. No other fish have absolutely nothing wrong. 6 pearls, 3 blue opaline gourami, 2 African butterfly fish, 3 jumbo swordtails, 2 female betta, and Vanilla/Snow White lobster; are the other inhabitants. It is a live planted tank.

 

[Fishfur]

There’s no such thing as black cotton mouth. That said, I don’t know why his lips & mouth area are so discoloured.

If you can get a glimpse inside the mouth, does it look the same dark colour?

It is possible that it’s bruising if he swam into the glass or other hard surface. If it is bruising, it should fade over the next couple of weeks and eventually disappear.

I don’t think it’s due to necrosis - dead tissue iow, because there doesn’t seem to be any inflammation and he’s eating - which I wouldn’t expect if the discoloured tissue was dead or dying.

I think this is one of those annoying ‘wait ‘n see’ situations.

 

[A201]

I've never seen that before. From the description it looks like the pictured Swordtail is the low man in the Swordtail hierarchy.
I don't think Swordtails lip lock battle like Cichlids do. I believe the territorial harassment is limited to constant chasing.
I agree with Fishfur, the Swordtail might have just power drove its mouth into the decor of glass, resulting in a bad bruise.

 

[70iselin]

A boo boo

 

[coralbandit]

If I remember correctly that will be an internal issue.
Possibly thyroid tumor pinching color nerve per Handbook of Fish Disease.
I have seen melanoma in black swordtails but no other color.

 

[Sb092]

If I remember correctly that will be an internal issue.
Possibly thyroid tumor pinching color nerve per Handbook of Fish Disease.
I have seen melanoma in black swordtails but no other color.

You may be correct. I found him on the bottom of the fish tank today. It looks like there is some labored breathing. And it looks as if the mouth is being eaten away or receding and is open. I attached the best pics I could. It is raining today, so I will do a water change tomorrow. I use a python on the outside water bibs, when cleaning. The python wont fit on any faucet in the house due to the faucet designs.
Poor guy. He even looks gray, like pale. Every other fish is doing just fine.

 

[A201]

That illness must be very uncommon. The poor guy most likely is a goner.
Amazing diagnosis, by coralbandit.

 

[coralbandit]

I can only highly recommend the book.
It is a great deal right now to boot.
Handbook of Fish Diseases by Untergasser, G.; Untergasser, Dieter 9780866227032 | eBay

If possible make sure book is in English as I believe many are in German.

 

[Sb092]

That illness must be very uncommon. The poor guy most likely is a goner.
Amazing diagnosis, by coralbandit.

You are correct. He didn’t make it through the day. By the evening, he was a goner. I did not immediately pull him out, because my vanilla lobster loves carcass. Unfortunately, no one touched him. I did pull the dead fish out and completed a water change. As of right now, no other fish are exhibiting any signs of disease. Everyone is eating, swimming, and seems to be ok.