What is this?

I've had several sponges start to grow in my temporary tank but I'm not sure what these are. They are a pink/purple color. At first I thought they were coralline algae but they are growing in shaded areas and don't grow anything like coralline. If they are sponges they are a color I've never had before. Kind of cool to see new stuff growing.

they are on the rock in the center of the picture.


and a closer view

 

I wonder if something was eating them in the old tank.

 

I thought about that but the only fish I had that would possibly eat sponges is still in the tank. I think it's because my sand bed had become a nutrient sink. Nitrate is about 0.75 in the new tank. Everything else is the same as in the DT. We'll see if they thrive as the tank moves forward.

 

I have some pinkish sponges under my big Birdsnest. I'll see if I can get a picture of them.

 

Like this?

 

Something else popped in my head. Is it this?

http://s171.photobucket.com/user/snowdogwgm/media/IMG_0700mush.jpg.html

 

Doesn't look like red bubble algae. Looks a lot like your first picture.

 

Ok, last week I found another newcomer. This is some type of sessile invertebrate. It kind of looks like a barnacle. It's about 1/2 inch long and has brillant red stripes on the side and black ones on top. Sorry for the crappy cell phone picture, couldn't get it in to focus.

 

Could it be some sort of scallop?