need ID (with pics) star, anemone, or urchine?

[revkev6]

I have had guesses of a type of starfish, an anemone or an urchine. it moves around the rock slowly, but doesn't really seem to be moving it's tentacles much. I cant tell if they are hard or soft. it's dark brown (as you can see) and a little larger than the head of an eraser.

 

[Anonymous]

It's a Diadema sp. Urchin. It should be reef safe but they often knock over frags if they're not glued down. They also enjoy munching coralline but in my experience it just makes it spread faster.

That looks like Gulf Aquacultured rock. Nice

 

[revkev6]

thanks guy, gaging by the other types of hitchikers I have it definately is gulf rock. don't urchines have spines pointing out? these only seem to be flat against the rock......

 

[Anonymous]

It will probably raise the spines occationally.

 

[Mihai]

Well, it's really easy to figure out if it's an urchin or an anemone: just check (maybe not with a finger) if the spines are hard or soft...
Am I missing anything?

M.

 

[sediener]

I had one of those show up in my tank a few years ago. Suprised the crap out of me when I saw this baseball sized black urchin grazing the rock one night... not sure if it is the same species but it didn't seem to hurt anything and I kept him in the display until he died a few months ago.

- steve

 

[ratherbediving]

I've got three from my live rock. Didn't even see them the first 2 months, then noticed one about dime sized. The other two were a lot smaller. About a month later, and the dime sized one is 2/3 the size of a baseball.... these things grow FAST. I have an acrylic tank, and am a little worried about one scratching the tank. However, so far they have stayed on the rockwork or the back of the tank.

 

[KensReef]

Definately an urchin.

 

[Anonymous]

Don't get impaled by their spines...venomous. Hurts about as bad a bee sting

 

[Mihai]

It probably depends on species and person on receiving end: mine only gets me like a mosquito (pain-wise, less itchy).

M.

 

[Anonymous]

True that. I'm a wuss when it comes to bee stings. Hate em. At least they can only get you once though. The urchin's got too many spines to count :lol: