Re: Lump on apisto fin
Posted: Sun Nov 24, 2019 15:00 pm
I arrived at my suggestion via a process of elimination, and a memory that's stuck in what's left of my brain because I remembered being unable to write the word without having to look it up to verify the spelling - I always want to write 'lymphocystitis', for some reason!
It doesn't look like any parasite that I'm aware of. It doesn't look like a bit of detritus that's got lodged in the fin. It doesn't look like a physical injury per se. It doesn't look like a bacterial infection. It could be a tumour but, if I've interpreted you correctly, it's developed rather more suddenly than one might expect a tumour to develop.
So IF all the above can be eliminated, one remaining explanation is a virus (there may be others that I've missed, of course!). When I first saw it I thought: "wart!" - which are caused by viruses, though I don't know whether fish are vulnerable to wart viruses! But I do remember reading that lymphocystis viruses are common in aquariums. As with most pathogens, fishes' anatomies and/or immune responses normally don't allow them to invade. A breach in the cuticle, though, changes that.
The cuticle covers the entire fish, fins an' all, though it's thinner at the gills to facilitate gas exchange. Such breaches may occur through relatively violent events - fighting, nipping etc. - but they can also happen via events which we'd assume to be relatively benign, such as being netted or a bash against a piece of decor.
As to treatment, I'm afraid I'm at a bit of a loss to know what to suggest. I guess I/we could do some reading-up. Is it better just to leave it and trust that the fish will overcome it eventually (like a human cold virus, maybe) ; or is it better to attempt to excise it and risk unnecessary trauma to the fish and/or risk spreading the virus (if that's what it is) further? I don't know - it's at times like this when I wish we had a vet handy (Fishgeek, where are you?!).
Random thoughts : quarantining is unlikely to do any good because the virus will be prevalent in the tank rather than be confined to the one animal ; provided conditions such as water quality, temperature and diet are optimal (I'm sure they must be, in your case) then it's unlikely that other fish will be affected unless their cuticles are breached somehow.
I'll do some digging when I can and let you know if I come up with anything potentially useful. Meantime, the above represents my best guess.
). It does appear it is similar to a wart in the way the virus works, and apparently will disappear in time with good maintenance, diet etc it also tends to occur on the extremities (like fins) more often because they are further away from the blood vessels, antibodies and immune system.
