red/magenta ish things?

hi guys i have this weird magenta-y reddish growth on my rocks they developed after i bought them, the rocks came from a very old established tank, there was some toadstool attached to some of the rock at one point but it died off (i assume) anyway, any input on wat these things are would be awesome, took the best pictures i was able to get.

 

also i dont think its a sponge, their a bit..."fleshy" o.0 or better said their a bit firmer then a sponge would feel...

 

Lack of coraline kind of tells me that the rock is not from "very old established tank" unless you bleach them before adding to your tank. Back to your question, these look like some kind of sponge, maybe a variation of Scypha sponge.

 

did you rip a leather coral off of that rock? when i did to one of mine, little sprouts of what was left behind popped up

 

Those are foraminiferans. They are a harmless amoeba that makes a shell for itself. They have the capability of moving, but rarely do. Foraminiferans by Ronald L. Shimek, Ph.D. - Reefkeeping.com

 

Awesome thanks guys, and to above, it indeed did come from a 4 year old tank, this is a less then 1inch spot on the underside of a rock, that has been magnified for easier viewing...sorry its not completely purple? o.0 lol

 

yeah there was some membrane left but it like melted away