Is dino sick or shy?

HHi all, I have had my salamander for a little over a month now. I love him and his well being is paramount to me. He lives in a 10 gal. Aquarium w/ aprx. A half gallon of water at the bottom. 3 feeder guppies live in the water but he does not eat them. His exact species is unknown to me as the pet shop guy sold him to me as a north american dwarf "somethin" salamander. He is small indeed only like an inch and a half...two tops. When I first got him he was being fed frozen blood worms...I have switched him to tiny live crickets and also when I place ghost shrimp to clean tank they get missing after a few days. He is pretty terestrial, hanging out on his driftwood or embankment (mispelled I'm sure) of river rocksor his favorite spot the boulder.he loves the back of the large boulder in there. Here is my delima he has been on the back of that rock for days now. Bugs and shrimp still coming up missing but I can't help but feel like he is lethargic.I clean tank regularly using gravel pump and he swims only in deer park or other natural spring water.thanks in advance for any answers as to why he never hangs out on driftwood or river rocks and always hides. Oh yeah one more thing I called the exotic pet doctor in raleigh and they said 72 degreed is optimal and thus I check the temp often it is always 72 to 74. There is a small screened off square on aquarium lid and I leave fan on normally to keep him nice and cool.I even try to avoid my overhead light and just use dim lamp cause I know he h8s light...BAD.

You really need to post a picture so someone can ID your salamander. Once you know the species, then you can care for it properly. It may be a completely terrestrial species with your current set-up harmful. I would not say that 72F is 'optimal' - some caudates can tolerate this temperature but colder is better.