I highly doubt you have a Cynops pyrrogaster as they are no longer supposed to be shipped out of Japan. At that size it is most likely a Cynops orientalis (which is also the most common species in the pet trade and at three inches is an adult).

If the fire belly newt is adapted to terrestrial life (as indicated by the rougher skin) then it can be difficult to reacclimate the C. orientalis to the aquatic life style.

See http://www.caudata.org/cc/species/Cynops/C_orientalis.shtml for more information as well as suggestion on how to reacclimate them... Keep in mind that this species does poorly at temperatures above 74 F and really should be kept at 68 F or cooler.

Ed