Yellow round sponge

[Swede's Reef]

I just received a zoa frag and it came with some small yellow critters. The zoas where dipped in Seachem iodine based coral dip. These guys seems to quite well and puffing up. Only in the tank for day since receiving zoa frag. Any ideas? yellow ball sponge? Good or bad... Thanks for your help.

 

[Swede's Reef]

And the one in between the yellow is ones. Looks like he has a feeder tentacle out.

 

[IKD]

The two on the side look like closed up zoas. Since this post is a few weeks old, is that what you see also now?