Question: Sign of coming metamorphosis?

Hey all,
Today I noticed a different behavior in my salamander larva (Eurycea cirrigera). He was propping himself up on the plants and it looked like he had his nostrils to the surface. Is this a behavior indicating lung development? I remember seeing a behavior like this just before morhping when I raised Bufo terrestris tadpoles where they would hover at or cling to something on the surface with their nostrils touching the surface.

Or could this behavior be an indicator of poor water quality? I ask the second question because I found the larvae in a stream a few weeks back and had him set up with a gentle air pump at home, but I had to move out of the dorms for 10 days (spring break) and forgot the air pump in the move, so he's been sitting in 3-4 in or shallow water (I have done partial water changes every few days though). In case it is due to foul water, I've another partial water change schedualed.

What do you all think?

Woah. Ignore the lung question, I'm used to dealing with amphibians with lungs and I forgot that Plethodontidaes don't have them! Still, the behavior intrigues me. I've done water changes...and there are better places to come out of the water if s/he needs to...any ideas?

Not sure about pre-morphing behavior - does he still have obvious gills? How is he acting today?

I have to use more than a dechlorinator for this crappy S. FL water. We had a problem w/ a small fish tank and finally became wise to the fact that Amquel wasn't enough on its own.

Good luck,
Dana