Why do leather corals close up?

[TWYOUNG]

Can anyone tell me why at certain times my leather is open wide with polyps extended, and a few hours later polyps are retracted and it's curled in on itself looking all gnarly. I realize it's normal but why? Doesn't seem to be strictly light related. Is it a feeding response of some sort?

 

[Freenow54]

I am following this thread because I almost lost mine completely. It used to be about 5 inches and behaved like what you described. now about an inch and has been that way for months

 

[Reef Puncher]

I accidently overdosed my magnesium and mine closed up for almost a week. i did some water changes and hes back open now. but he will close occasionally if i pour AB+ in the water or if a fish bumps him a little too much or if its night.

 

[Sleeping Giant]

they just act like jerks sometimes, mine does that about 2-3 times a week for a couple of hours lol

 

[albano]

they just act like jerks sometimes, mine does that about 2-3 times a week for a couple of hours loll

They just want you to know who’s boss!

 

[HawkeyeDJ]

Mine closes multiple times (2-3) a day. He does this if a snail or other invert climbs on him. Usually he's out again within the hour. Sometimes I think he is just napping.