Pincusion Urchins

[sh2000]

What would be a reason why these urchins would shed its spines ?
water parameters are all OK so do they shed when they are about to die ?
or if an animal attacked it ? or a rock might have fell on it ? I have one on the SB about 1 inch in diameter and it lost all the spines and the CC is having a ball eating him should ai remove it or let them eat ?

 

[natclanwy]

Sounds like it died I have had two urchins in the past die for unknown reasons one of which I had for 2 years the other possibly did not acclimate slow enough.

 

[sh2000]

these lived 5 months.