pincushion urchin shooting out sand

[comycus]

My pincushion urchin was releasing sand from the top of its head earlier this evening. Did this several times today already. Is there anything wrong with it? It only chooses to shoot out very fine sand right in front of my wavemaker, like mini sandstorm.

[yikai]

i think its pooping. their anus is at the top of their heads

[limsc]

i think its pooping. their anus is at the top of their heads

My tuxedo urchin always do that...

[comycus]

i think its pooping. their anus is at the top of their heads

lol i figured tt was their "out", but seems like pooping sand. Just wanna check if anyone's urchin does the same thing. Fascinating to watch at first, but then when you have fine sand flying all around the tank, doesn't look tt cool anymore

[Thexder]

Its urchin sh*t