Help me ID 5 critters, please!

[lucyloo]

I posted about some of these before, but now I have photos

#1: Small brown and white snails with varying degrees of stripes. Some have a lot of brown, some have almost none. The biggest are pea-sized, they come out mostly at night but I can see them anytime if I search. They're definitely not sundials.

#2: Red blobby protrusions under this live rock shelf. They don't move, and they have grown within the 2 past years - that rock was dry base rock when I put it in the tank. Some stick out maybe 3-4mm. Some kind of sponge, maybe? (Notice the mystery snail on the right near the blobs? He is one with more brown)

#3: Olive colored mound with an emerald green "crack" that opens to different widths. This is about an inch long. Another sponge?

#4: Orange polyp? I used to know what this thing was. How can I encourage it to reproduce?

#5: Big ol' hermit. Left-handed? Is he mean?

Thanks guys!

 

[ophiura]

#1) Collonista snails - beneficial grazers, stay small
#2) Red foraminiferan Homotrema
#3) Sponge
#4) Button polyp eg Palythoa-ish
#5) I wouldn't trust it (most hermits are highly opportunistic...larger species can be quite a problem). I'd banish to sump or refugium...how big is it?

 

[theappe3]

I have a few of those big red hermits. I personally have never had a problem with them and they are quire large. They actually house turbo snail shells, so you have an idea about how large they are. Again all hermits are not the same even though they might be the same species. Mine could be passive and your hermits can tear everything up.
My suggestions.... keep an eye on them.

 

[lucyloo]

Wow!! Thanks for the great info, both of you, and quick replies to boot.
The hermit is in an orange turbo shell now. He is probably about the size of a quarter when viewed from the front. So far he's not caused any trouble. He is rather slow and seems to really enjoy just picking at the algae, caulerpa, etc. He switches shells pretty often, and always picks ones of similar shape and size! I will definitely be scrutinizing his every move

One more question:
Is there anything special I should be doing for the button polyp? It's been there 2 yrs. and faithfully opens every day. I wish it would spread. However, I only have regular fluorescent lighting (egads... I know that's bad...) It seems happy besides the fact that it's not reproducing. I have coralline growing, 2 kinds of caulerpa, and no cyano (along with all the other normal critters - pods, dusters, etc.) so do you think that's OK?