Sea Urchin

[s.a. boy]

I have recently bought myself an urchin (he's very cool and active) I was not told that they can be deadly to your tank if they die. (I know I should have done more research on him before I bought him but you kind of expect a LSF to tell you that he can KILL YOUR TANK)
Anyway !
My Q is should I keep him ?
2 : How long do they live for?
3: how long will I have to get him out my tank if he dies before he kills my tank?

 

[nacl-h2o]

The urchins will eat up your coraline and they are like bulldozer, and are known for knocking over corals and rocks. These are the primary reasons most people don't keep urchins. I've never heard that they will poisin a tank, but they will decompose quikely and drive your ammo up so if one dies remove it asap. That dosen't mean some aren't toxic.

 

[mlm]

They are in the same family as starfish. I don't think you will have any problem with toxins.

 

[rich1515]

I have one in my 75 and you are right, he wails on the coraline on my rocks. I was going to take him out but my wife really likes it in there for some reason.
Here is a pic of him below my fish

 

[plum70rt]

I have 5 urchins in my tank, 4 pencil and one long spine,they are all over and they do knock stuff over time to time, munch a little corraline, they were given to me they are cool critters but if I had to start over I would leave them out, for now I just deal with them
I had one die just fell apart no ill effects

 

[ophiura]

The pencil urchin is actually the only urchin in the hobby that really runs a risk of eating things other than algae.
Otherwise, they are considered to be fine, so long as it has room to move. They can grow quickly, and are not great for smaller tanks.
Most people who have them graze on coralline algae report that it grows back very quickly in a healthy system and is not considered a drawback at all. They can bulldoze rocks and frags that are not properly attached, which many animals can do.
If it is a long spined urchin (Diadema, the spines are venemous, and you must know where the animal is at all times. IMO, this is not a species for small tanks, because you can easily bump into it.
Sea urchins are close relatives of (but not in the same family as ) seastars, brittlestars, sea cucumbers and crinoids. They are in the class Echinoidea, the phylum Echinodermata (meaning spiny skinned).
Like all echinoderms, they are not tolerant of salinity, pH, alk or temp fluctuations. Tank conditions should be prisitine, and a long acclimation is typically a good idea. They can and will die of acclimation stress just like Linckia and other forms, though they tend to be a bit more tolerant of short salinities (depending on the species).
They are not overly toxic (most species), except that they will produce an ammonia spike in the tank, should they die. They can easily live many many years, and perhaps much longer. There is debate on this issue, especially how to determine it in wild specimens.

 

[scotts]

When I was first starting up my tank I bought a sea urchin. He was the cutest little bugger and he was cheap. He would pickk up a little bit of a rack and wear it like a hat. My kids and I giggled about that for a couple of days. Then I realized he was eating my coraline. Not just a little, but leaving white rock every where he went. When I took him back to the lfs they said "I did not know that was what they ate". Since then they have never had an urchin in their shop.
Scott

 

[danrw84]

yeah they are cool but i wouldnt get one, they knock over rocks too much.

 

[s.a. boy]

Thanx for all your comments people. I have noticed that he does love coraline, but I don't think he is eating quick enough to cause me any problem.
Old Yeller Tang : THe Pic of the second urchined is what I have in my tank the LFS said he is a pencil urchine. Is that correct if not can you give me the correct make? coz the pic's I have seen of pencil urchins don't at all look the same but mine looks exactly the same as that pic!
Thanx again!!!!!!

 

[s.a. boy]

Old Yeller Tang : What do you mean by rock boring?
Do you feed him anything extra like brine shrimp or......?

 

[musipilot]

We have two long spines, and a pincushion. They do eat coralline, but it grows back. They do occassionally knock things over, but only when I havent' secured them properly
One way I found to lower their coralline destruction is to feed them. All three of them LOVE freeze dried krill. The long spines especially go nuts for it, they will "run" across the tank at feeding time, and plant themselves at the top center of the tank with spines out of the water, waiting to have krill dropped onto them. They then work it into the middle of their back where their mouth is. They munch on it for hours.
Great creatures, and a lot of fun to watch. They also add a certain "Wow, that ain't no freshwater tank" mystique to the aquarium.
As far as their toxicity, don't get poked with the spines, trust me on that one. I have read that if they die, they can be toxic, but again, in a larger system, I wouldn't worry.
I had to move one from one tank to another, if you ever have to do this, a spagetti strainer and a tupperware work well. Scoop him underwater with the strainer, and 'pour' him into the tupperware to travel.
We have one that is 3, one is 2 1/2, the other about 6 mos. old.
Here's the oldest:

 

[ophiura]

Sometimes people get loads of the rock boring urchin in LR. They can often come in as itty bitty things and then suddenly appear, a long time after the rock is added.
I agree with Musipilot. They can be easily fed as well. Shrimp pellets are another easy thing to feed, and if you just drop them between the spines (even on their back) they can get it down to the mouth easily.