whats up with chromis dorsal fins?

Does it mean anything when a green chromis puts his dorsal fin up?

I have been watching my chromeys and they seem to put their dorsal fins up at random times. At first I thought it was just when they wanted to move fast or handle better. I noticed they would do it right before they were about to attack one of the other ones, and whenever they are getting fed.

Other times it seems like they put their fins up and then don't take off. That got me thinking, do chromis use their dorsal fins to communicate with the other ones? Like horses (equine not sea) pin their ears back when they are angry. Do chromis do the same kind of thing but with their dorsal fin?

I was just wondering if anyone knew. I'm going to keep studying them, but I wondered if anyone noticed that as well.

this is what I am talking about

dorsal fin up-

dorsal fin down -

*pics are not of my fish.

 

lmao. I just noticed there is another thread almost identical to this one... I feel stupid now haha. I should really pay more attention.

 

I use to have a betta and noticed that when it was mad it would flare up its fins. on my tang I notice that he uses his dorsal for control. When he darts across the tank he will put his fin down and when he does tight manuvers he puts it up. So with dorsal fin up it could be many things. Maybe it is mad or maybe it is just moving around.

 

with certain fish it's different things, can be a sign of aggression or flaring up in self defense or can be a mating thing as well