spikes falling from urchin
 

recently my pin cushion sea urchin has been losing some its pins/spikes so i was wondering if anybody has seen or know what to do in this situation...it is not quite as active as he used to be either so i was not sure what i should do, thanks

Usually when this happens (at least to the atlantic pin cushins that I've had experience with) it is from long term starvation. After they eat all the algae in the tank they have to be fed a lot of substitutes such as nori or some of the better algae pellets. Other causes could be poor health for any reason, I don't know of any that shed their spines, but maybe there are some that do.

Poor water quality (ie. high nitrates) will cause them to lose spines as well.

rlm2005 ++ poor water quality, maybe its time for a water change, ... WATER CHANE the wounder cure for all things

I think it's probably on it's way out.

NOt sure if this is helpful but I have a longspine that from the time it was a golf ball will lose/break spines and two years later still doing the same thing he is now larger than a softball.