Crustacean / Amphipod (?)

[icejam]

Just set up first aquarium and discovered those guys:

Sorry for potato quality but they only come out at night.
Do I need to burn my house down now or those are OK?

Also are those zoas I have growing there?

Thanks.

 

[cristata.reef]

Yes it's a gammarid amphipod, which are common and beneficial CUC. The zoas are actually palythoa. To me they look like P. mutuki, but P. heliodiscus could also be a candidate. Actual species doesn't really matter (and is very difficult to determine without a geographical location of the wild colony). Just make sure to be safe when working with or around them