Sea Urchin Hitchhiker

[AlfredE]

I got some live rock about 6 weeks ago for a now 4 month old tank. Came with some interesting stuff - three sea squirts, a couple of turkey wing clams, some cup coral and various sponges. All still alive so far - apart from some sponges that were DOA. I'm feeding Seachem Zoo and Phyto Plankton and using ZK Sponge Power. There are no fish in the tank. Today a small urchin appeared (body diameter about 1") :

It's black in color - other than "black sea urchin" does anyone recognize the species? Any special care needs other than just letting it eat algae? Also, I feel like I should be looking for some live zoo/phyto plankton for the squirts and clams - any suggested brands? Thanks!

 

[Skynyrd Fish]

Great looking rock. I don’t have a good answer to your question. I’m sure someone will chime in.

 

[Hemmdog]

Pencil urchin

 

[LobsterOfJustice]

Short-spine or rock-boring urchin