Electric Lab problem

[MarkDad54]

Pam,

I have a 29 gallon tank which only contains 6 Electric Labs (2-3 inch). On two these fish, I noticed black algae looking discoloration on their heads. It looks like the black algae that grows on the rocks in the tank. Did they get this discoloration from digging around the rocks? And if so, is it harmful to the fish?

Thanks,

Mark

[Pam Chin]

Hi Mark,

I have seen this before, and I am not sure exactly what it is, but I suppose it is some kind of fungus. It doesn't seem to hurt the fish other than it discolors them. I am not sure where it comes from, I suspect fish farms. I hate to medicate fish if I am not absolutely sure what it is, so I suggest increasing your water changes; quanity and frequency, and really scrub your tank down well, and hopefully it will eventually go away. As long are your fish are having no ill effects from it, this is the best way to go.