What's this?

[Dcolognesi]

Got home from work and see these??
Good or bad??

 

[Dylan J.]

its a sea urchin, it eats algae

 

[Reefing Madness]

Pencil Urchin

Saltwater Aquarium Inverts for Marine Reef Aquariums: Pencil Urchin

 

[Dcolognesi]

There's 2 of them and they randomly showed up....

 

[StevenBell]

Normally you would have to pay for them!Those are the kind of hitch hikers you want!!!

 

[Reefing Madness]

Gotta watch those though. They can uproot rocks, and knock stuff around a bit.

 

[Dcolognesi]

Thanks for the help!

 

[Dustin1300]

If you have acrylic I'd also get rid of them to a local reefer with a glass tank. Known to scratch and reportedly "eat" acrylic while they are scraping algae off. They'll clear out a TON of coraline algae rather quickly too.

 

[Dcolognesi]

You think I should get rid of one of them in order to keep most of my coralline? I don't have much as it is

 

[afamousjohnson]

Even wi5h one in time it will be gone but they eat algea also. I like the purple but I like urchins too. Some can find your zoas appetizing also. My black spine is the only control I have over the crazy pink and golds that were growing in my sump.
score on the hitchhiker pickup

 

[reefginget]

sounds like a freebee!