I only had them come out of the water if the water was too hot in the summer. They , I believe, in keeping them, to be 99.9% aquatic. I have kept Paramesotriton caudopunctatus ,Paramesotriton guanxiensis/fuzhongensis , & Paramesotriton hongkongensis so far.
Ive had one like to stick its nose out of the water while sitting on a rock that broke the surface but that's it.
Cataldo
p.s. Rob is right, you should check the ammonia(NH_3/NH_4) levels as they can be a factor if the filter is bad/clogged, or the tank is a "new" set up. Remember in an established tank, the ammonia levels should always be 0ppm but in a NEW tank they will surge to 6ppm or more and reduce as the biological filter becomes established. If the tank is "cycled" you should then check nitrates(NO_3). That's of course, where water changes come in handy. In freshwater aquariums, nitrate levels of 40ppm or less is okay. I check my chlorine levels weekly out of the tap. My local H2o supply always comes in at 0% luckily for me.