Possible baby black urchin

[OldmillXxX]

I have been watching a black ball on a new piece of live rock I added to my tank. The rock is very open and covered in coralline and mushrooms. I noticed yesterday that the ball has small spikes coming out of it, maybe 8 or so spikes looking like sharpened pencil lead. It has not moved since I first spotted it four days ago.

I do not have a photo right now because I am at work, but will see if I can post one tonight. It will be pretty hard to get a photo with my little camera, but I will at least attempt it.

If someone has a photo of one could you post for comparison?

Thanks in advance!

 

[OldmillXxX]

It hasn't moved at all, so I will assume it is not an urchin. I will continue to monitor and see what it turns into...if anything.

Here is about the best pic I could get. Any ideas?

 

[OldmillXxX]

Anyone have an idea?

 

[74nautique]

I had a very small black spiky ball down in a hole that didn't move for a couple of weeks, then I noticed it would move out of the hole for a little while then go back in. Then it disappeared and I found it later, turned out to be a small urchin and it started growing very rapidly, eating coralline algae, I put it in my sump.

 

[OldmillXxX]

Cool. I have been thinking about getting one, but have held off because they are known to eat coralline and I am just starting to get it back.

I'll have to keep watching and I'll let you know if it ever moves. It is right on top of the rock. I would have thought if it were going to lay still for a while, it would have done so in the dark.

I also found what I believe is a gorilla crab with eggs in the same rock. Actually, there are two in there (one quite small) and I think another that 'jumped/dropped' out when I put the rock in the tank! I'll have to keep a close watch and try to ID better.

I'll keep you posted!

 

[OldmillXxX]

Anybody know for sure if this IS a baby urchin?

 

[Brock Fluharty]

Longspine urchins do eat coralline, but they do not deplete it. They graze on it, which sends spores of the algae off, which actually helps to spread it. I would guess that it is an urchin. On coral forum, under propogation, there is a guy who had one reproduce.

 

[The steven liu]

From the picture it doesn't really look like an urchin.
An long spine urchin's needle would be much much longer than whatever is poking out of that black ball in the picture. But I am not sure what that is. Anyhow, urchins do move slowly, like 1 inch a day kind of speed. Sometimes they do sit in one spot for days. So don't throw out that hypothesis yet.

 

[romunov]

Looks more like a snail. Search for "Scutus".

 

[Brock Fluharty]

My urchins move like 100 inches per day. Not 1...

 

[OldmillXxX]

Well, I have been watching for signs of movement for days. I have moved the rock to get a better look and still, no movement. I thought the same thing, that the spines would be longer, but since I have never seen an urchin this small I thought, maybe.

To date it still has not moved from it's spot in the photo above. Maybe my eyes are playing tricks on me, but is does appear that the spines are longer, and more/less of them from day to day. It has what appears to be a small section that comes down and around the rock, almost like if you were to stretch your gum out and place the part in your fingers on your chin.

I will continue to watch for any signs of anything and post back. If anyone has other ideas now would be the time to post.

Thanks for the suggestions on snails, I will look for them; although, I would have thought it would have moved if a snail. I'll check.