What is this thing?

[Airwolf]

Any ideas as to what this is?

Tanks was started with dry rock and sand.

I do have astrea snails and a frag of zoanthids that it could have hitchhiked in on.
Haven’t added anything in 2 months, first time seeing it.

 

[monkeyCmonkeyDo]

Abalone or possibly stomelia snail.
D

 

[Airwolf]

Next question, good or bad to have?

 

[ISpeakForTheSeas]

If it has a row of small holes anywhere on the shell, I'd guess abalone of some species too. Both Stomatella and Abalone are good. I'll do a little more looking, but I'm not aware of any other snails with similar features, so these seem like a good guess for now.

 

[SaltyAllergy]

Any ideas as to what this is?

Tanks was started with dry rock and sand.

I do have astrea snails and a frag of zoanthids that it could have hitchhiked in on.
Haven’t added anything in 2 months, first time seeing it.

I have this same little guy in my tank, I first though of a nudibranch, but no, just a stomatella snail!

 

[WheatToast]

Stomatella snail. Good algae grazers and they will breed.

 

[Airwolf]

Still see it around occasionally. It has gotten larger.