mabey algae?

[Aquaria]

so i got this white.....fuzz, hair on my live rock. i cant take a picture its to small iv been reading a fungus but the attached pictures look nothing like what i have. it looks like small hairs with filter feeding ends like the way a piece of xenia looks only WAY smaller and there are 1000s of the tiny things
there only on one peice and the rock was kept in a sealed bucket for close to 4 months how could anything survive? should be dead base rock or so i thought ummm another thing is the tank has been lightless for the entire month it has been set up so i wouldnt assume algea but in this hobby its anyones guess lol.