The Bump Is Back

[Donya]

I can't find my old post on this (maybe it was deleted since it would've been pretty old), but need to bother people for some thoughts again. So, a while back my engineer goby turned up with two bumps, on on his head and one just behind the head on the back. The one on the head is completely gone, although it left a strange little crater. The one on the back went down to the point where I thought it was gone, but it in fact never went away since I saw it from time to time for several weeks thereafter. At that point the guess was either bruise or small tumor, but tumor would seem a bit strange since it went away so quickly. In the last two weeks though, the bump on the back has gone and swelled up quite a lot again and stayed that way.

The fish is about 11-12" long from the last time I measured and the bumb is about the size of a pencil eraser. Again, there's no discoloration I can see on it, no raw patches, etc...but upon closer inspection, it looks less like just a swelling and mroe like a big bubble under the skin. The goby had his blind side to me once this week and didn't realize I was in the room for a change, so I got a really good look at it, although photographing it will be pretty well impossible. It's like some kind of gigantic blister, but I can't think what in the tank would be able to cause that (I would suspect the heater, but it has been unplugged since before the lump swelled up again). I'm guessing it's not filled with blood or solid tissue, since when the light hits it right I can see through it ever so slightly. It looks like it must be a really thin layer of skin that the lump is sitting under. I've just been letting it be, but I thought I'd toss out the extra bubble-like observation in case it's starting to match a definition for anything other than "mysterious lump."

 

[SkiFletch]

The only other thing I could think of Donya might be an Isopod of some sort?

 

[Donya]

The only other thing I could think of Donya might be an Isopod of some sort?

Ugh...I don't know much about those guys. Mostly I've only seen/heard of are the harmless ones that the goby eats sometimes and the bad ones that latch onto the outside of the skin/tongue. Are there types that can get under the skin? Also, if it could be something parasitic, is there something I can or should do to get rid of it? So far I haven't been seeing anything seriously negative happening as I've been letting it sit, since the fish is still grumpy as usual and eating well. I haven't done anything to this point since I worry that if it turns raw it could get infected.

I saw one page's recommendation but I don't know if it applies:
http/www.everything.com/Health-and-Parasitic-Diseases/

A variety of conditions caused by several parasites are commonly termed “gas bubble disease.” Although the process of infection is not completely understood, it seems that air bubbles attach to the bodies of affected fish and create conditions favorable to bacterial growth. Water that is supersaturated with oxygen or nitrogen has been implicated in certain, but by no means all, cases.

In its early stages, gas bubble disease can be treated by pricking the affected area with a sterilized needle and releasing the enclosed air bubble through massage (the fish should be carefully held underwater during this process). A wide spectrum antibacterial should then be swabbed on the wound site. Advanced cases are nearly always fatal.

I don't really see how bubbles on the outside of the fish turn into bubbles under the sking, so I'm a bit dubious of the description there, and it's not a site that's on my trustworthy list. The only other things I've read about so far for causing bubbles under the skin don't match.