Ever seen a tuxedo urchin spawn?

[Jax15]

The other day I noticed that my tuxedo urchin had climbed to the top of a rock, and started spewing powdery stuff from its top. It continued to pour out for 20 min or so, seemed never ending (the fish loved it! A mid-day snack). I've heard of clams doing this, but have never seen anything like this with my urchin and wanted to share.

 

[Jax15]

Not sure if the video upload worked, here's an image: