I have had one of those, that is exactly what it is trying to do. I only got rid of mine as it was bulldozing over my frags to get to the coraline algae that was on my rocks. These are really cool looking urchin with their orange 'eye' and blue spots.
+1 To the spawning. Mine did that, too. Very cool!
+1 to the bulldozing. My long spined urchin Irritates my anemones embedded in rock niches to the point that one day they are beautiful and puffy and the next day they are so small I can hardly see them in their nook as the culprit is moving his way over the spot. Takes a day or two before they come back to normal.
I am Contemplating rehoming him but we love the guy!
But I love my nems, too.....