Cichlid Behaving Strangely...

[mindwarpstudios]

I went away for just under a week (all feeding was pre-measured and delivered on schedule by the caregiver) and this is what I came back to:
 
Water Stats Normal:
Nitrate 20ppm
Nitrite 0ppm
Ammonia 0ppm
 
35% Water Change performed on day of return (similar WC done the day before I left).
 
All inhabitants behaving normally (neons schoaling; otos, amano and nerites cleaning 24/7) except for one of my Cockatoo Cichlids.
 
I was under the impression that the one in question is a Male (definite Cockatoo plume to the dorsal fin, dark tips to pectorals and leading edge of dorsal fin, though none of the "leopard style" mottling to the fins otherwise that I have come to expect...  but that's one reason why he was chosen).  I am open to correction based upon the photos...
 
I have one other Cockatoo in the tank who is almost completely yellow (very minor mottling to one section of the tail, darkening of the tips of the pectorals and leading edge of the dorsal fin, and a single faint spot directly in the middle of each of the flanks), this was agreed to be a Female at the time of purchase and is behaving completely normally and swimming/eating/pooping well.
 
The one in question is settled just above the bottom of the gravel, using its various lower fins to gently support itself.  It seems to swim gently between two different hiding spots: in a cavity in the underside of a tank ornament, in a coconut cave; luckily, there was a little time spent today in the hollow of a piece of driftwood that afforded the photos you see below.
 
It hangs out without moving excessively, watches the other fish, and breathes a little faster than I would expect.  The most peculiar aspect to her behavior is the fact that while the fish is constantly "chewing," it rarely actually closes its mouth.  In fact, I would describe the action as more of an opening and relaxing (vs. actually chewing).
 
From my observations over the past three days, there is absolutely no swelling of the body/eyes, clouding of the eyes, fuzz, white spotting (small or large), apparent skin lesions, fin damage, scale damage, loss of balance...
 
I have did an additional 20% WC yesterday and have one planned for tomorrow.  Additionally, I have already put a touch of salt into the aquarium and held back feedings in case this is a form of bloat.
 
I have attached photos to aid and my specific questions are at the bottom...
 

 
 
Is it possible that my He is actually a She (and the other She is in fact a He), and She's turning eggs in her mouth?
 
Is it possible that He has something stuck in his mouth?  ...For this long?
 
Can any experienced Cockatoo keepers give me any other queues to look for in case it could be something that a "wait-and-see" approach would make worse?

 

[Essjay]

I've never owned that particular strain of cockatoo apisto (mine have always been the strains with orange fins with black mottling), but the one in the pic is definitely a male, judging by the fin shape. I would be a bit concerned about this fish. He won't have eggs in his mouth - my experience is that the only time males have eggs in their mouths is when they are eating them. It is possible he could have a piece of gravel stuck in his mouth/throat. That happened to a bolivian ram in my tank, the reason I changed to sand. Apistos do take mouthfuls of sand when looking for particles of food and yours could have attempted to do the same with gravel.
if he does have somethign stuck, I don't know what to advise. My ram did get rid of the gravel after a few days but she was never the same again.
 
 
Edit 
<-- the photo is my female apisto in breeding colours for fin-shape comparison.