Help Identify this Sea Urchin

[cogreywolf]

First, let me say that I will post a picture on Tuesday. This may not even be a sea urchin.
Description: The spines are purple in color, but are not spines. The tips are rounded and form a very hard shell around the body. Kinda looks like a turtle from the top. The LFS had a very difficult time pulling him off of the acrylic tank. They were unable to identify him as well.

 

[cboyfan2020]

pencil urchin?

 

[cogreywolf]

He may be a type of pencil urchin. The spines are not really spines. They form a shell around the body. When you look at him from above, he has a turtle like shell. The spines form this shell and actually makes a smooth like surface.

 

[cogreywolf]

Here is a photo. I was unable to take a photo from the other side.

 

[ophiura]

Very interesting. Never seen it in the 'trade' but guess it is out there. Probably Colobocentrotus atratus. The shape and small spines is an adaptation for living in high wave energy environments. Generally called a shingle urchin.
Don't really know about whether it is totally reef safe or not.
From: A German site

 

[cogreywolf]

Do you know anything else about it. Like water conditions or temps, etc... As far as reef safe, I'll let you know.

 

[ophiura]

They are found on rocky shores, in places like Hawaii. High energy environments generally, though not sure if they need that. Otherwise, same conditions as for other urchins. Lots of rock to graze on, mature tank, stable/pristine water conditions (higher end specific gravity around 1.025), temp 78-82 range, I would imagine. What are your water params...how old is the tank?
BTW, is that a glass, or acrylic tank?

 

[cogreywolf]

Well, currently I have him in my nano reef, which has been setup for about 6 months. I decided to put him in there until I knew a little more about him. The water quality in the nano is great, 0 ammonia, 0 nitrite, 0-10 on the nitrate(might be the test kit), specific gravity around 1.024, temp 80. The nano is an acrylic tank. However, I was thinking of adding him to my 75 FOWLR glass tank. Is there a concern with glass or acrylic? The water quality in my 75 FOWLR is not as good as the nano. My nitrates are higher in there, obviously. However, the 75 has been setup much longer. I have a good amount of coraline algae for him to eat, if thats what he eats.
P.S. Is it true that urchins chew on power cords?

 

[scotts]

Jut to let you know I had a sea urchin. Let me say had. I am not sure what type it was, but man did it eat my coralline. It was only about 3/4" in diameter, but it would clear a rock in a day or two. When I took him back the lfs said they did not know that urchins ate coaralline.
It is too bad because he was pretty cool. He would grab a little piece of rock and carry it around on top of him like a hat.
Scott

 

[simm]

Most urchins will feast off of coraline. However this one beeing reef safe Im not sure. Iv never seen this kind. However some urchins are reef safe and some are with caution.

 

[sea goblin]

Most people that i have talked to say that they have improved growth of coralline algae due to the urchin's munching which spreads the algae spores. In general i think most sea urchins are reef safe but certain precautions need to be taken. Rocks and corals must be securely glued to prevent the urchin from being able to topple the rocks and corals over. I have 2 urchins in my tank, and thus far have been a great joy to have.
Sea Goblin

 

[ophiura]

The part about eating coralline is generally true, but in mature tanks it should indeed not be a major problem as coralline growth is fast (and space is a priority- so open space is quickly colonized). In younger tanks this can be an issue, but usually not long term if conditions are ideal for coralline growth. My general concern with acrylic is with scratching by the wrasping teeth (and spines I would suppose), which can be pretty hard. It is a potential, but perhaps not major, issue. The part about securing rocks is, however, quite important as urchins have a reputation of being 'bulldozers.' This is generally unwarranted, and is usually the fault of the hobbyist who did not properly secure the rock structure. The urchin was just being an urchin I wish I could tell you what it eats, but I haven't a good clue. That will be a wait and see I am afraid. In general, I would expect it to be better off in the larger system, due to the availability of food. Slightly higher nitrates should not be a major issue, if that is the only difference in water quality. Significantly higher? Hmmm, well, a potential problem if you are going to undertake major water changes to get them down (echinoderms do not like fluctuations in water parameters).

 

[toddpolish]

my Royal Urchin plowed thru the hair algae (within a month) and now he's going for the coraline on the rocks. I was going to bring him back to the LFS tonight.