Black Slug looking thing...ID PLEASE!

[Mrseptember15]

I've seen a couple of these in my tank, they hang around the coral and I can't seem to cut them off with my razor so I'm just wondering what they are!

Please and thank you

 

[reefnetworth]

stellatoma? honestly cant remember, i just know they are reef safe cleaners/algae eaters.

 

[Sk8r]

not a stomatella. Looks a bit like a nudibranch.

 

[Mrseptember15]

Yeah, I don't think it's a stomatella either because it doesn't move as much. One of them actually went under a coral and now it has a stalk of xenia on top of it. idk whats going on but I hope it's reef safe! I just had one of my colt corals disappear

 

[greenbean36191]

Well, my first thought when I saw the pic was that it's an ovulid, but I'm kind of confused by the descriptions.

You said you can't cut them off with a razor. Does that mean that it's got a solid attachment to the rock or that it just had a strong grip? Have you seen it move? Does it move like a snail? What do you mean it has a stalk of Xenia on top of it? Did it just crawl under a mat of Xenia or is the Xenia actually growing on it?

What does it feel like if you touch it? Does it feel like a soft layer over a hard shell?

 

[Mrseptember15]

I posted this same question on another forum and got this:

Guitarra Sp (black encrusting sponge).

It's isn't shell hard but it has a really thick grip on the rock. I try to cut it out but it doesn't budge.