id my urchin please

[VacavilleFC3S]

he came as a hitchhiker in the ricordea i picked up today, he's about the size of a large gumball

 

[philter4]

Looks like a reef urchin, Echinometra viridis, the problem is if it came from the pacific I have no idea. Reef urchin is common here in FL and is in the rock in shallow water with the ricordia, once it is in a wholesaler or store tank any urchin that was in the system could have moved to the rock.

 

[Airwolf75]

I agree, I have 4 that look like that and they are harmless.

 

[alfiser]

reef safe short spined urchin, Echinometra lacunter or echinometra mathei, they are harmless but will bore into rocks

 

[Airwolf75]

None of mine bore into rocks after 3 years. I believe the rock boring urchin is a different species than the short spine reef urchins, but they are often grouped into a generic category with a few other urchins.

I have seen at least three different kinds, this urchin pictured, a slightly larger more oval, purplish colored one, and a black one that bored into rocks.

I can also say from experience, that this one with the white around the base of the spines, stays really small.

 

[VacavilleFC3S]

it actually does look like it has bored into that rock. theres several (4-5) dimples in the rock about the same size as the urchin.but whatever it does it does very slowly because theres coralline encrusting every hole and even the one it's in right now. is there any way i can encourage it to leave the rock?

 

[Airwolf75]

Just check it at night and it will be out and about. Just hit it with a stick and knock it over, then it will be easy to pick up and move. If you try to grab it to slowly, it will lock down and be tough to pull off.