Algae blenny won’t close mouth!

[JohnnyTJ09]

I had my algae blenny for a few months now and he’s been doing great, this afternoon I noticed that his mouth is open. I’m not sure if something is wrong or not but I think there is. Can you guys help me ou?

Edit: his mouth has stopped being wide open and is now looking better

 

[najer]

It is a common thing, my jewel yesterday.