Does anyone know what this is??

[Livbaby21]

I’ve had angelfish for a while. I just noticed this on my fish. Does anyone know what this is?? Please help.

 

[Andy Sager]

This is an ulcerated wound most likely caused by a internal worm that has opened the fish to escape then either the flesh has died back or has been picked off.
If it were me, I'd place the fish in a hospital tank and first treat with a dewormer then with an antibiotic to help keep the wound clean as it begins to heal then moved to a quarantine tank until it totally heals.

Hope this helps.

 

[Livbaby21]

This is an ulcerated wound most likely caused by a internal worm that has opened the fish to escape then either the flesh has died back or has been picked off.
If it were me, I'd place the fish in a hospital tank and first treat with a dewormer then with an antibiotic to help keep the wound clean as it begins to heal then moved to a quarantine tank until it totally heals.

Hope this helps.

It does thank you! How would I go about cleaning the tank he is in now to make sure the other fish don’t run into this problem? I have another angelfish and a pleco in the tank with him right now

 

[Andy Sager]

It does thank you! How would I go about cleaning the tank he is in now to make sure the other fish don’t run into this problem? I have another angelfish and a pleco in the tank with him right now

For starters, I'd use a dewormer in the main tank as per directions because most need 2 doses, 1 to kill the worms then 1 to kill what hatches from the eggs. After that, you just need to do your routine water changes and cleaning to keep the water pristine.
The pleco may be the one who made the hole worse so I would definitely isolate the injured fish from the other fish. You shouldn't use antibotics in the main tank tho due to most of them suppressing or killing the biological filter bed. This is why it should be done in a hospital tank. If you need guidance on setting up a hospital tank, I explain it all in post #2 here: Quarantine tanks and Hospital tanks, are they really different?

 

[Livbaby21]

For starters, I'd use a dewormer in the main tank as per directions because most need 2 doses, 1 to kill the worms then 1 to kill what hatches from the eggs. After that, you just need to do your routine water changes and cleaning to keep the water pristine.
The pleco may be the one who made the hole worse so I would definitely isolate the injured fish from the other fish. You shouldn't use antibotics in the main tank tho due to most of them suppressing or killing the biological filter bed. This is why it should be done in a hospital tank. If you need guidance on setting up a hospital tank, I explain it all in post #2 here: Quarantine tanks and Hospital tanks, are they really different?

Thank you, do you know how this could have happened? I haven’t added anything new to the tank since I got the angels.

 

[Andy Sager]

Thank you, do you know how this could have happened? I haven’t added anything new to the tank since I got the angels.

Internal parasites often come in with the fish so it's not necessarily anything you did. However, this is why you have to be extra careful where you get your fish from and quarantine everything before adding to your main tank(s). Intestinal worms are common in most bottom feeding fish or fish that live close to the bottom but in the case of Angelfish, the fish can be become infected through live foods they may be fed. That means it could be traced back all the way to the breeder or anywhere the fish has been before your tank.
I will say that this is a rather extreme case. I have suspicions that the pleco is partly responsible for the wound being so large. Usually a worm makes a bump in the area then a pimple on the outside then a small hole through the skin that if left untreated, becomes infected or gets fungus on it. This opening is way past that.