Urchins. What are they good for?

[TomToro]

've got two tuxedo urchins eating my red turf Algae like it's candy. I'd like to mix it up a little in the other tank with some urchins.

Q:Are all urchins reef safe? If not, which ones should I watch out for at the lfs?

Q: Do any urchins eat detritus?

Q:Are there some urchins that eat specific algaes? I can see the tuxedo eating turf and coralline Algae in my tank, but leaves the Valonia alone.

Q:And this is a big question: Do any urchins do damage to acrylic surfaces with their (teeth or whatever they eat with)? Are Tuxedo urchins known for this since they can plow through coralline?

Thanks,
Tom (Urchin Fan)

[mscarpena]

I have heard that urchins can damage tanks. Never seen it myself, but thats the rumor. To my knowledge they do not eat detritus and not all are reef safe. Tuxedo's are reef safe, but all urchins are bulldozers and will knock things over including corals. As for what urchin eats what algae I am not sure, but most will eat algae and a lot of it. Once there prefered algae is gone they may eat the other kind.

[TomToro]

I have heard that urchins can damage tanks. Never seen it myself, but thats the rumor. To my knowledge they do not eat detritus and not all are reef safe. Tuxedo's are reef safe, but all urchins are bulldozers and will knock things over including corals. As for what urchin eats what algae I am not sure, but most will eat algae and a lot of it. Once there prefered algae is gone they may eat the other kind.

I better look it up on the net. I'd hate to have an urchin scratch the heck out of my acrylic. Hard enough keeping it scraped without scratching it.

Thanks for the info,
Tom

[Airwolf75]

If you want one to eat detritus, check out Heart Urchins.

[mod0522]

+1 on them being horrible bulldozers and mine really decimated my coralline algae population.

[Elysia]

"Pencil" urchins will eat soft corals and gorgonians, at least the ones from the Caribbean/Florida -- Eucidaris tribuloides.

[J. Montgomery]

I have a common rock-burrowing urchin. I have it b/c it looks cool. They eat coralline algae.
http://i159.photobucket.com/albums/t133/baronpsjosh/BlueTortUrchin.jpg

[TomToro]

Thanks for the info, folks! I'm going to look up the heart urchin now.

By the way that rock borer looks very cool.

[Airwolf75]

I'll also agree the pencil urchin is the worst bet.

I also keep the pacific rock boring urchins and the viridis ones from the caribbean, 3 of each. in 5 years they never ate a single coral, but strip the rocks of all algae.

[rkaires]

I have a few long spine urchins, one is in my acrylic frag tank. Never noticed and damage that I didn't inflict. They do a great job on all types of algae. If you keep your viewing panes clean they stay off.

[ralphie]

I have a tuxedo urchin and like it. It will eat my coraline algae but that just spreads it and it does grow back. It is comical what he ends up carrying around with him. I have found a thermometer, coral frags and a live hermit crab upside down. I hardly ever glue my coral plugs or frags down and he has very rarely ever knocked any down.

[cknguyen3]

I have a pincushion and he is a pain.
From grabbing my frags, snails, and what not he rearanges everything small he can grab.
Unfortunately he ends up dropping my frags in dark spots out of reach where they eventually die, so im costantly battling him for my new frags.
He also is a lawnmower he clears most of my rocks of algae and corraline to.
Right now im on the verge of taking him out and trading him back to the LFS.

Just my personal expierance with this urchin.

[peasofme]

i have 2 rock borrors but they dont seem to be taking care of my algae. i may have to look into a pincushion. my blenny kills my snails.

[d2mini]

The pencil is the real bulldozer. My long black spine urchin is much more gentle. My purple pin cushion seems gentle so far but still too early to tell. He is comical though.