Pretty sure it's the bad kind. Here's the description from the place I got the rock saying they are ID's by black eyes: Cirolanid Isopod
Here's another pic:
Hopefully that’s all of them. Tbh I was going to buy rock from them but never thought about these guys coming in with it. I’ll stick to my rock. Good job.
I will say, predatory isopods aside, the rock is really cool. Lots of interesting stuff going on everywhere and instant color, which I do realize will probably change off as the sponges recede.
I will say, predatory isopods aside, the rock is really cool. Lots of interesting stuff going on everywhere and instant color, which I do realize will probably change off as the sponges recede.