Large yellow/white lump on my Springer Damsel

[Yamo25000]

When I first noticed this spot on my damsel, it was white. I did some research and thought it might by lymphocystia, so I moved it to a quarantine tank, but now it looks yellow and less like a lump.

Aquarium is very new (about 4 weeks old) and tank mates are a blue spotted puffer, another springer damsel, a flame fin tang, a flame fin blennie, and a royal gramma.

I don't have the ability to get hard numbers on all my water conditions, I just have color-coded test strips. The salinity is right around 1.027

Is this a disease, injury, or something else? And should I quarantine?

 

[Jay Hemdal]

Welcome to Reef2Reef!

That isn't Lymphocystis. It is most likely a bacterial or (rarely) a fungal disease. However, its location - right in the abdomen, is in a VERY serious spot! What tends to happen in these cases is that the fish's abdomen is breached, and the infection becomes systemic - the fish's internal organs have become infected. I see that the fish's right pelvic fin is almost totally eaten away. I'm afraid there isn't anything you can do for this fish - sorry!

It is unlikely that this issue will spread to your other fish, but you need to ensure the water quality is kept at its best. A specific gravity of 1.027 is a bit high - natural seawater is 1.025. If you can locate a good ammonia test kit, you should buy one to ensure that the ammonia level of the tank is kept at less than 0.25 ppm ammonia.

Jay