I have a 3.5 year old ishigame (Japanese pond turtle). He's always very expressive so it's easy to tell how he feels. He's also always extremely friendly towards me. Tonight I heard a strange squeak sound come from his tank and when I checked on him he looked frightened. Then he slowly opened his mouth and looked a bit angry. He was breathing a bit hard. I thought something had spooked him. He then went into his water dish and occasionally opened his mouth as if he needed to throw up. After a while he settled down and now he's fine. He had no other symptoms and he's never been sick. Does anyone have any idea what that was about?