Anemone with gapping mouth

[Haddonisreef]

I have a orange bta that every couple of days will gape its mouth open in the mornings. The tank has a rose bta in there also and i have never seen it do this. I feed then about 2/3 times a week a combination between silver sides and pe my-sis, brine, and blood worms.
All of the other animals are happy in the tank so i'm not sure why this guy is not looking happy sometimes. The only thing i can think of is this is how he does his dodo.
Any thoughts would be greatly appreciated!!:bum:

 

[Haddonisreef]

Well after watching the anemone this morning i have come to a conclusion. I turned the lights on before the normal time and with in a few mins the anemone closed its mouth and began to inflate back to normal, tentacles also began to inflate so it must be its way of releasing its dodo.