Hi everybody, I started a 20g reef about a month and a half ago, and I've found about 6 of these little hitch hikers in my tank, I took the photos with my iphone so the quality isnt that great, but from what I can tell it is mostly black with black bands on the arms along with transparent/light green bands. The largest one ive found is about an inch and a half diameter. I wanted to know if these were okay to leave in the tank or should I be picking them out as i can catch them? Any help is much appreciated. thanks
These are good guys and will eat left over food and detritus. They hide in the rocks, and when you feed you will see a million little legs sticking out trying to grab food.

