I don’t know how this get in my tank. I only have corals for now. It move around, look like a nudibranch or something like that.

[Eyomael]

 

[Timfish]

My guess would be a Stomatella snail. If it is it will have a shell and they are beneficial. FWIW, a lot of stuff will be on coral colonies, most will be beneficial but some will be unwanted. Dipping corals before adding them to your system will minimize introducing pests.

 

[PotatoPig]

+1 Stomatella snail.

Probably hitch hiked in on a coral. Good guy. They eat a wide range of algae and readily reproduce in reef tanks.

Weirdly, not something you readily see for sale in LFS or online.

 

[Eyomael]

My guess would be a Stomatella snail. If it is it will have a shell and they are beneficial. FWIW, a lot of stuff will be on coral colonies, most will be beneficial but some will be unwanted. Dipping corals before adding them to your system will minimize introducing pests.

thanks for answering. I don’t see any shell, look very soft to me. Is like a snail out of the shell or like a nudibranch, May be a flatworm. Is like 1cm long and half wide

 

[Eyomael]

+1 Stomatella snail.

Probably hitch hiked in on a coral. Good guy. They eat a wide range of algae and readily reproduce in reef tanks.

Weirdly, not something you readily see for sale in LFS or online.

I don’t think it have shell, it looks very soft to me

 

[PotatoPig]

The red thing on the back looks like the shell.

Here’s a video of one - your photo looks similar to mine, just with a reddish shell, IME the colors vary.

 

[kchristensen8064]

Definitely a stomatella, the shell is just like a fingernail, its not a traditional snail shell. Stomatellas are some of the best clean up crew you can have, awesome hitchhiker!

 

[Timfish]

What they said, the shell is very rudimentary.