Is this normal for a Sharknose Goby?

[jostafew]

Hey everyone! I just got a new Sharknose Goby that I've been waiting a couple months for, and now that it's been in quarantine for a couple days and moved close enough to take pictures of I see something goofy with its mouth; it looks like it's gaping way open and its gills are spread way open! The mouth never really closes, it just hangs open while it breathes. I'm a little concerned that either it's damaged somehow (and I should be taking it back to the store) or somehow it's gaping for lack of oxygen in the water?

Anyway, I got a few good shots of it so please let me know if it looks odd!

Thanks in advance