Snorkel

My apologies if this has already been discussed, if the life cycle of the proto Xeno involves incubating inside somebody, then bursting out of the hosts mouth, would that hold some significance or clue as to why the sj's have that snorkel on their helmet??? Everybody's assuming it is some sort of breathing device while in spaceflight when in fact it could be an incubator of sorts, maybe even a right of passage for the species (reaching sexual maturity etc), any thoughts