Long spine urchin reef safe?

[Omakoshark]

Hi. I have a small long spine urchin that I want to move into a reef tank. Are they reef safe?

 

[Copingwithpods]

Yes in the sense that they won't eat your corals but beware that they are strong and can bulldoze stuff. Recently had mine pluck a very expensive zoa off a plug never to be seen again, I Googled how to slap an urchin but decided against it.

 

[DaneGer21]

Although cool to look at, mine is banned to my algae tank, and no longer permitted in my display tanks. They WILL knock something over eventually that you’ll be mad about haha

 

[Omakoshark]

Haha most of my coral has grown onto the rock. So I’m not too concerned. I have a few frags in the sand but I’m going to build a makeshift frag holder.

 

[Omakoshark]

He just doesn’t seem too happy with the tank I have him in now.

 

[Blknovass]

I had a pencil urchin very cool but he would knock over my rocks. I got rid of mine some time ago and never looked back.

 

[Omakoshark]

I think I’ll put him in, but if I have any problems, he gets to go back home.

 

[rgulrich]

Here's a quick read on diadema urchins:

Diadema antillarum (long-spined sea urchin)

animaldiversity.org

And yes, even though there was algae in the system, I have had the occasional "mowing" of acropora by a diadema, including some of the corallite walls. They also do pretty well at re-processing coralline algae.
Some Cardinal fish prefer them as nurseries for their young (one of the reasons I have one in my 300), and they a great job on most types of algae (the other reason).

Cheers,
Ray

 

[Jowieg]

Mine was doing well until the algae started becoming sparse. I have a nepthea tree that started losing flesh at the base and caught the urchin eating it while lights were out. I am not trying to actively feed it nori and hope my leather recovers.

You can see the part that has been eaten away at the base. It was previously all thick and has become thread bare.

 

[Jowieg]

Meant to saw now actively trying to feed it nori

 

[trevorhiller]

Updating this thread as I seem to be having problems with mine after a few months with little to no issues. I had lots of hair algae, but now it only grows in areas where the urchin can't access. I've noticed four seperate frags/small colonies with damage to them over the last week. I've seen similar damage in the past but not to this extent.

The frags almost look like someone ran them through the band saw with the tips/sides perfectly cleaved off. I think mine is going to be relegated to the sump for now.

I imagine for a tank with large colonies it wouldn't be much of an issue and might even stimulate some growth, but from my experience this past week I'd say use caution if you have younger SPS colonies & frags.

 

[rgulrich]

Mine still enjoys trimming the acro colonies on occasion. And some montipora. Oh, and many other LPS and SPS s as well. I think it's either turned into a hobby of some sort for it or it's constantly letting me know that it's not finding enough palatable algae in the reef. The newer frags can really take a hit (unfortunately), but like you imply the older colonies pretty much shrug off the little damage it does.
Cheers,
Ray

 

[DaneGer21]

Mine is still banned to the algae filter/sump. Almost 4 years total down there!

 

[trevorhiller]

Mine still enjoys trimming the acro colonies on occasion. And some montipora. Oh, and many other LPS and SPS s as well. I think it's either turned into a hobby of some sort for it or it's constantly letting me know that it's not finding enough palatable algae in the reef. The newer frags can really take a hit (unfortunately), but like you imply the older colonies pretty much shrug off the little damage it does.
Cheers,
Ray

I wouldn't mind if he would go after the montipora or something else quick growing, but he ate most of my new frags I just got a week ago. Literally 3/4 new frags and one older colony. He must have expensive taste

 

[rgulrich]

He must have expensive taste

...or a calcium deficiency perhaps? Sometimes I think they do it just for attention. Like when an L. variegatus/variegated urchin manages to pry loose that new frag and wear it around the reef like a new hat...sigh.

Cheers,
Ray