Hitchhiker Urchin

[Samw]

Looks like a spiny Sea Urchin. I noticed it maybe 2 weeks ago. It came out of nowhere and hasn't moved from this spot.

http://www.hyperdream.com/~samw/reef/Critters/Urchin/img_7094_crop_std.jpg

[StirCrazy]

Nic one Sam, this is the same type that J&L sent to me as a sub for what I wanted, they are a rock eating urchin but pretty cool.

Steve

[Samw]

Thanks Steve. Do you know the name of this urchin? Is this one sold at stores? Which urchin did you specifically ask for?

[marie]

I have one of those that came in on some fiji rock. It is now huge, spines included it is about the size of a tennis ball and chows down on corraline like crazy :biggrin:

[Coldwater]

It looks almost like a slate or pencil sea urchin.

Matt

[StirCrazy]

this is an Echinothrix calamaris urchin from my guess, If it has the thicker sets of spines with open tips. If all the tips are closed then it is an Echinothrix spp. what I ordered is an Tripneustes sp. you will see that the Echinothrix calamaris or spp is Destructive or harmfull to corals and toxic or harmfull to people and food wise they are both herbivorous and carnivorous.

Steve

[BMW Rider]

That urchin looks very much like the one I have. Its an Echinometra viridis, sometimes called a white ring urchin. I've had mine for six months and its been no trouble. Usually its tucked away out of sight in a crevice during the day.

[sumpfinfishe]

Cool find Sam just be careful around those spines :mrgreen:

[Samw]

Hi Steve. So you actually ordered an urchin but they shipped you the wrong one. Not only did they ship you the wrong one but they shipped you a destructive non-reef safe urchin?

BMW Rider, did you pay for your urchin or was that a hitchhiker too. Thanks for the ID. I'll check it out.

I just got the book Reef Invertebrates today and the only urchin I see that looks close to it is Echinometra methaei. The book doesn't show each and every species of urchin. It says that it is rock-boring which explains why mine is in the same location on the rock ever since I saw it. Anyhow, I'm not sure if I want to keep this urchin or not. If they are venomous, its just a matter of time before I get pricked by it and die (well maybe not die) or at least feel excruciating pain. :lol:

[Samw]

This could be it.


http://www.reefs.org/hhfaq/pages/main_pages/faq_rock3.htm

http://www.reefs.org/hhfaq/img/urchin1.jpg

"It is possible that this particular urchin is Echinometra mathaei which is a common hitchhiker on Indo-Pacific rock. Other Indo-Pacific hitchiking urchins may include Pseudoboletia, Tripneustes, Paraselinia, and Echinothrix species. Echinometra mathaei bore holes into rock while using its spines to hide itself. It is an effective algal grazer but can irritating to other tank inhabitants with its burrowing habits. "

I think most of my livestock comes from Indo Pacific so this could have hitchhiked in as an urchin larvae or baby urchin, and after all these years, it finally showed itself. :question:

http://www.jaytorborg.com/Underwater_Gallery/0901%20Image38%20500.jpg

http://www.jaytorborg.com/Underwater_Gallery/0901%20Image38%20500.jpg


http://digilander.libero.it/scubabob2/Rosso3/images/urchin07.JPG

http://digilander.libero.it/scubabob2/Rosso3/images/urchin07.JPG

[Samw]

I just found a 2nd one in my tank. They come out at night and they hate the light. As soon as I turned on the lights to take a pic, they moved away. I didn't know they moved so fast. They are neat.