urchins

[JenniferL]

As far as I know, I think that once you notice them loosing spines there done for. I think its a stress thing, they can be very sensitive. How long did you acclimate him? I acclimated my first one too fast and it lost its spines in less than a week and died. I bought a second and did it much slower and he's been in my tank and do fine for 6 months now.