Lipstick Tang (Naso Elegans) with dorsal fin blocked erect

[marcoc]

Hi guys,
about one week ago I have inserted a Lipstick Tang (Naso Elegans) in my reef tank (105 Gal). There were already a Paracanthurus Hepatus and a Zebrasoma Xanthurum. After some days of adaptation also with a rigid net in the middle of the tank, it is now four days that it hold ALWAYS (day and night) the dorsal fin erect. It looks like it is blocked and the fish is not able to relax it down.
Have you ever experienced or heard something like that?
Thanks.

 

[homegrowncichlid]

its just making itself look bigger than it is.

 

[marcoc]

Yes, I agree. That's surely the case. I just wonder if it is going to harm it to keep it always open or if it is a sign of constant stress that might result in its loss.
It would have been useful to know if anybody had experienced something of the kind and how it had ended up. Thanks.