pin cushion sea urchin

[debbieraptors]

Just purchased several large pin cushion sea urchins. Can anyone please tell me what they eat? I offered it a piece of shrimp, but is wearing it rather than eating it. I have plenty of algae and live rock in the 55 gallon tank, established tank of three years with rubble base, using the T5 lights suspended over tank. My mushrooms and xenia are doing great, but I want to know what to fed the urchins. I also feed phyoto feast and copepods in this tank.
Deb

[sharper]

I don't know anything about sea urchins, so I can't help you there.
But I'm just laughing because I'm imagining a sea urchin wearing a shrimp for a hat.
LOL

[johnski]

they will eat macroalgae and coralline algae, not sure if they eat microalgae as well

[JENnKerry]

They are an algae eating machine. I have one in my 125. After they settle in, they will also appreciate meaty foods like shrimp and krill. If you are attached to the corraline on your back glass, then I would not get one. They will devour it.
As for the hat, mine has a mat of about a dozen zoos on it. Pretty funny.

[debbieraptors]

Thank you for your replies. I bought three pin cushion sea urchins, each one about the size of your fist. I split them all into separate tanks which all the tanks have a lot of corraline algae.
You stated they eat macro algae? Does this include hair algae?
I also have beautiful mermaids cups, red macro algae, xenia, and tons of mushrooms, plus caulpera. Can you please tell me if they will eat the red macro, xenia or mushrooms? I am not quite sure what is meant by "macro" algae. Is corralline algae considered macro?

[johnski]

i'm no algae expert , so i suppose the best description i can offer about what is a macro-algae is , if it looks like a plant rather than a thin coating of green then its a macro-algae.
here are some descriptions of the macro-algae i have in my tank and what i've seen the urchin eat

grape algae , both red and green ( caulerpa racemosa, not sure if the red variety is called racemosa as well ) , the urchin eats this

bryopsis ( hair algae ) never seen the urchin eat this , i still have to manually remove this.

a red algae thats kind of like a grass, the urchin eats this

another green algae, i think its called sawblade algae, the urchin eats this.

i never considered coralline algae as macro-algae, just coralline algae, the urchin will eat this

as JENnKerry says it is an algae eating machine, it will soon rid the tank of what i've mentioned and probably more types

[johnski]

oh , forgot to mention , yes it probably will eat your red macro-alage, am unfamiliar with mermaids cups

[Sk8r]

They eat just about anything that coats rocks, some species [hairy red/white striped] eat caulerpa, and all will scrape rock quite happily. They nosh on my coralline, but don't take off enough to daunt the growth at all. Won't touch diatoms, but like the short red stuff.

Mine is a real acrobat working in and out among sps with no problems. He won't touch corals.

[johnski]

Sk8r, it was actually your post about the hairy pin-cushion urchin that helped me decide to get one, one of my better decisions, lol

cheers mate

[Sk8r]

Ah! I'm delighted he worked out for you. Mine has certainly helped my tank a lot....and he's ever so much quieter than a rabbitfish!

[debbieraptors]

You guys were right on. I split up my three urchins and they took huge amounts of corraline algae off the back of the glass and rocks. They are happy little algae eating machines.
Also you were correct when you said they will eat red macroalgae. I had to move my beautiful cultivated mermaids cup and red macros to another tank. This stuff is huge....grows like a beautiful plant...it is about 14 inches high and very thick with a lot of red branches. I will try to get a pic and post it.
Good thing I have 12 large tanks to accomodate everyone.
Thank you.
Deb

[Ryanqk]

yeah i had one that ate up every piece of vegitation in the tank except for some of my coralline. he is gone now

[Cathy1]

Yeah a lot of people put them in thier tanks for algae control so and I don't think that it would want much to do with shrimp.