A Question About The Engineers Neck

Shilliam Watner
MemberOvomorphJune 09, 20122381 Views6 RepliesShilliam Watner here. I was wondering if anyone noticed the gill slits in the Engineers neck, particularly right in front of the carotid arteries? The first Engineer we see at the beginning of the film has no slits in his neck but the one that is awakened from stasis does. What do any of you think the reason for this is? You can get a good look at the gill slits in the youtube video below.
Spoilers
http://www.youtube.com/watch?v=Dm1gX6KVntU&feature=plcp