black long spined urchin
I have a 3 inch long spined urchin which I have had for about 6 weeks. He is healthy and is eating well. For the last few days I have noticed that 3 of his spines are starting to turn white. Can anyone tell me why this is happening. The water parameters are fine with 0 nitrites and 0 nitrates. I do water 15% water changes every week. temp is 79 degrees. Salinity is 1.022. Tank is a 70 gallon. One fluval 404 and an undergravel filter.
Thanks very much.