Longspine urchin sick?

[Bob Escher]

I have a long spine and and a pincushion Urchin in my tank. The pincushion looks and seems to be doing just fine. The long spine one I find spines all over but recently I just noticed that although he has plenty of spines they are all very short. He moves all over the aquarium looks healthy. But just very short spines. Any ideas
Water parameters are good. The pin cushion one is doing fine
Thanks

 

[James M]

Any pics ?
There’s not much you can do with urchins. If it’s still moving and grazing on algae then it’s okay

 

[Bob Escher]

Thanks

 

[Bob Escher]

Any pics ?
There’s not much you can do with urchins. If it’s still moving and grazing on algae then it’s okay

Here you are

with a filter