Interesting Filter feeder and Sponge ID help

[MatthewSS7]

This post is just out of general curiosity. I’m assuming these are simply harmless filter feeders of sorts. For some perspective, tank is about 4yrs mature. The sponge is mostly growing in dark spots underneath live rock. The new rock I am curing has a newer growth on top as seen in pics. There is another shot of this same type of sponge that has fallen into a normally well lit spot.

The other filter feeder is growing in a well lit area next to a red fan worm for some size comparison. Also included another shot of it with a hermit visible off to the right for additional size comparison. Thanks for looking. Happy reefing!

 

[MatthewSS7]

One additional pic of the filter feeder. I have tons of pineapples but this thing is a bit more unique. To me anyway.