Sea Urchin Loosing Spines

[Smaster121]

About 6 weeks ago we noticed that my black sea urchin seemed to have flattened. Most of the spines on top were leaning over so that the urchin was 'flat'. I know it had crawled under a rock at one point so I assumed that was the cause. But it never really recovered. The spines came up a little, but never back to normal.

Lately the spines have been falling off. It seems OK in all other respects. It is mobile. Color looks good. Its just going bald on top.

Is this normal?

[Kermits Reef]

Hard to guess not knowing about your tank. I will address some likely issues. Some fish eat urchins. Urchins have the ability to flatten and law down the spines. Water conditions may be causing him to die, ck ammonia and nitrite and nitrate. Some chemical could cause death, copper products. How long have you had him? Temperature?

[Paul B]

I had a business for a few years of collecting purple urchins using SCUBA and shipping them to hobbiests for algae control. I have kept hundreds of them and when their spines start falling out they are usually dying. I have seen a very few of them recover. Urchins are very sensitive of water conditions, especially metals and are used in some labs as an indicator of water conditions. It could also be that it is starving. They eat a lot of algae.

[Smaster121]

Temp 78. Got him as a hitch-hiker on my very first piece of cultured rock back in February. Ammonia, Nitrate and Nitrite near zero. Tank has a very low load. One Yellow tang, a cleaner shrimp and a few snails.

Starving huh? Could be. I have been 'blessed'(?) the past couple months with zero green algae. Zero cyano. Only a light coat of brown on the glass and sand, none on the rock. Plenty of coraline algae though. And the snails have been dying off too.

Tank is 40 gal plus a 10 gal sump, 2" of DSB, about 25lb of rock. Filtration is a protein skimmer plus the small foam block in the overflow. 1 95W white +1 95W Actinic runs about 11 hours a day.

He was thriving through my new tank syndrome episodes of hair algae. Now that the tank has stabilized and the algae is under control it could be he is starving, along with the snails.

Suggestions?

[WFPetrie]

You could try target feeding him with nori or a seaweed sheet. Put the food near him, or put the food in the tank and the urchin on top of it.

[Paul B]

I used to feed them fresh spinach that I ran under hot water for a few seconds to soften it. They would eat it like crazy.
I stillthink yours may be too far gone though.

[montourcreek]

Paul: Did you collect them from the NY area?

[Paul B]

Yes I collected them in New York. I still do sometimes. There is a place on the South shore of New york that has very fast moving water. There was all kinds of tropical fish there. I could get about 100 purple sea urchins in about 20 minutes. There was also butterfly fish, triggers and seahorses.

[Kermits Reef]

I agree with above he is probably a goner. Near zero is not close enough to zero for some inverts...../ spellcheck off

[Smaster121]

My LFS did not have Nori or seaweed sheet. They did have Spirulina Discs which I tried.

Are there toxins in the spines that may be esaping as they fall off contaminating the water? I've been removing them.

He's loosing them like crazy.

I tried spinach tonight. He hustles off it like it's HOT COALS.

[Kaos]

My sea urhin had his spines falling out a few months ago , but he recovered fully and is now scooting around the tank. He should be very happy since I currently have plenty of algae for him to feast on. :p

[Paul B]

The urchin spines are not poisonous. I have dozens of them stuck all over me. They disolve in a few weeks. They are made of calcium and you can leave them there. The thing is croaking and when it dies the fish will tear it apart and have a feast or you can remove it when most of the spines drop.
I only have one more week to dive here I should collect a few for my tank.

[Smaster121]

Well, I started this thread on 10/3. Rough guesstimation means that the poor urchin started loosing spines about mid August, well over a month ago.

The poor devil is now bald. But he keeps plodding along. The body appears pretty robust. It is full and plump. Not at all emaciated like I was expecting it to get. My kids tell me they think they see new spines growing. Frankly I think it is wishful seeing.

But I have to admit he (she?) doesn't look like he/she is dieing...