Black Widow Tetra HUGE internal red lump HELP!

[Alicia11]

Hi all,

I hope its not too much trouble to ask but I have kept various fish for approximately 13 years and I have never seen something like this on any of my fish.

I have searched the web high and low and I can not find anything that could help me out.

I have a 38l AquaOne tank, water temp and 24 degrees Celsius, PH neutral 7ish and no ammonia as tested last night. they eat good quality tropical flakes I do a water change once a week slowly as to not shock them with the temp change I use filtered water and I dechlorinate and add streseze.

I only have 6 fish in my tank at the moment 5 Black Widow Tetra's and one Corydorus (yes he needs a friend).
I have gravel and a few plastic plants been in their for ages.
all the fish are relatively new about a month old all purchased at the same time.

Yesterday I noticed one of the smaller Black Widows has developed a large lump just behind his Dorsal fin but inside his body. he is still eating fin and swimming fine but I have no idea what to do, the shop where I bought him told me to bring him in they will swap him over for free and she will freeze him (put him down) I don't have the heart yep big sook.

Does anyone know what this possibly could be and how I can manage it at all or if the girl in the pet shop is right.

I am not sure what the best way to upload an image is.

 

[Delapool]

Hi, welcome to AA

Was wondering how quickly this has developed? And if it is pushing the scales up or growing over them.

Possible options could be an internal tumor pushing out. Lymphocystis (cauliflower disease) is another.

If it developed more quickly then something like a bacterial pimple is possible (possibly triggered by a parasite in centre or some damage to the scale somehow). These tend to erupt, heal and fish carries on.

 

[Alicia11]

It developed quite quickly I'd say within a day, it has changed slightly red on one side and clear with a dark centre on the other side. It is still the same size.

I have done some research and looked at cauliflower disease but it doesn't look like that.

I had a chat to the shop that sold him to me and he mentions parasite aswell.

I don't have a hospital tank set up I am floating him in a plastic bag (fish one) in my tank so I can maintain the water temperature and use some water from the tank with good bacteria to keep him going. I am changing the water regularly in the bag and topping up the tank with clean water no contamination of water.

I have added a bit of salt as that is what the guy at the shop recommended.

Should I do anything else or just keep doing what I am doing if it is a parasite how would you go about getting rid of it? Or them?

Thankyou for your response I appreciate it!

 

[Alicia11]

Oh and the scales don't seem to be affected too much he has had one it 2 stick up but that only seems normal as he has a lump. They are definitely not sticking up like they do with something like dropsy.

 

[Delapool]

Dreadfully late here. I'd look into a salt dip (gets around the lack of a QT) and then metronidazole if needed.