Three Identifications, please.

[Katy410]

I saw a smal snail/slug creature in my reef, and I apologize for not having photographs. It is small, with two antennae, and moved quite fast. But it is NOT a stomatella.
The second identification is this:

The quality is awful, I apologize.
And finally, this was on my live rock since I got it. It used to be quite brittle and black, but seems to have grown healthy. A purple "slime" is underneath. It is also on my tank walls and powerhead. It's tough to get off. What is this? I assume GSP, but just to be safe...
Here is some of the "slime" on my glass and powerhead:

Thanks!

 

[Katy410]

Make that four. I have a picture of he snail I described;
And I have these little worms.

 

[dingusplease]

I saw a smal snail/slug creature in my reef, and I apologize for not having photographs. It is small, with two antennae, and moved quite fast. But it is NOT a stomatella.
The second identification is this:
View attachment 236188
The quality is awful, I apologize.
And finally, this was on my live rock since I got it. It used to be quite brittle and black, but seems to have grown healthy. A purple "slime" is underneath. It is also on my tank walls and powerhead. It's tough to get off. What is this? I assume GSP, but just to be safe...View attachment 236189
Here is some of the "slime" on my glass and powerhead:
View attachment 236190View attachment 236191
Thanks!

1. Could it be a large amphipod? I have some that are up to a centimeter long...
2. Not sure, possibly a stomatella?
3. Coralline algae, it's slow growing and good for your tank. Not green star polyps, wouldn't be so hard to get off.

 

[dingusplease]

Make that four. I have a picture of he snail I described; View attachment 236196
And I have these little worms. View attachment 236197

Calcareous worms, no real effect. Harmless filter feeder.

 

[Katy410]

1. Could it be a large amphipod? I have some that are up to a centimeter long...
2. Not sure, possibly a stomatella?
3. Coralline algae, it's slow growing and good for your tank. Not green star polyps, wouldn't be so hard to get off.

Ooh, thank you. What are those little not-GSP things? I have tried to get them off before. They just release this cloud, and close up.

 

[dingusplease]

Ooh, thank you. What are those little not-GSP things? I have tried to get them off before. They just release this cloud, and close up.

I don't know what you mean by " the stuff used to be black" or "slime", but the purple algae on your powerhead and glass (which is actually rough to the touch and very hard) is common coralline algae.

Gsp has a thick mat that can be up to 0.5 centimeters thick, and usually appears white when viewed growing on the wall of an aquarium.

Do they actually have any depth? Or is it very thin? Coralline algae most often is encrusting, and therefore has very little to no real thickness. I am completely baffled by how it could be releasing a "cloud" or be closing up.

 

[Katy410]

Okay, I'm so sorry for my terrible wording. Yes, the algae, or the "slime" that I mentioned before, is Coraline. That's what I assume is under the GSP, since they are on a lavender base on my live rock. Not so much "base", but they are on top of a substance. When I tried to take my brush and scrub off the GSP, after hearing that I should, a "cloud" of the remains blew off. And the heads, throughout the entire colony, were "sucked up". I don't know the entire term for that, I'm sorry. But to have the coral take in it's flowery feather part kn the top? If you know what I mean.

 

[dingusplease]

Okay, I'm so sorry for my terrible wording. Yes, the algae, or the "slime" that I mentioned before, is Coraline. That's what I assume is under the GSP, since they are on a lavender base on my live rock. Not so much "base", but they are on top of a substance. When I tried to take my brush and scrub off the GSP, after hearing that I should, a "cloud" of the remains blew off. And the heads, throughout the entire colony, were "sucked up". I don't know the entire term for that, I'm sorry. But to have the coral take in it's flowery feather part kn the top? If you know what I mean.

Very sorry about that -- didn't mean it to come out so rudely!

I think I understand better now. You probably had some Cyanobacteria, which does in fact feel slimy and will scrub off easily, and may look to release a cloud of bacteria as you scrub it off.

As for your gsp, most corals can retract to close up if they are irritated, but this is not a bad sign. They often close up when you're cleaning the glass, fragging, them, transporting, them, or touching them in any way, but should open up again within the next few days.

Sometimes, corals may close up for days at a time, but most likely they will open agains soon, it's natural!