Pin Cushion Urchin and water changes

[BarbaraAlys]

Hello all. I am fairly new to the salt water world, and this is my first post. I have a pin cushion urchin, been in the tank for about six months. Ever time I do a water change, after I have started putting the new water back in he comes out of his den and ... well ... he does is part in spawning, if you know what I mean. It goes on for maybe 4 or 5 minutes. One, does anyone one have any idea why he does this only when I'm adding the new water, and two is this good for my coral/tank? Thanks!

 

[lapin]

Howdy and welcome
Never had one do that maybe someone here knows a bit more about what urchins expel
#reefsquad

 

[35ppt]

Urchins can be compelled to spawn from temperature fluctuations.

 

[saltyhog]

I've never had one of mine do that but I always match temps with my water changes. This is no threat to any of your tank inhabitants. In fact it seems to promote polyp extension on my corals when my trochus snails and RFA's spawn. Think of it as food for you filter feeders/corals.