P. guangxiensis differs in colouration from fuz in that it is generally darker (a brown-black colour as opposed to the olive-brownish of fuzhongensis) and lacks the black and orange in the dorsum and flanks. I would say that these guys are fuzhongensis, which are still quite variable in the tone of olive-brown. The tail colouration fades to orange and grey towards the edges, which is also a character of fuzhongensis
They are not chinensis, as fuzhongensis and guangxiensis are separate from all other paramesotriton (other than the new laoensis) in that they are covered in large warts. The other paramesotriton , though having very granulated skin, lack the high density of skin glands.
I think that, as most captive animals are w/c without locality data, a lot of pictures on the web are only named with (sometimes ill-informed) educated guesses.
Wouter - if you have the fuzhongensis descriptive paper, is the picture of a specimen in colour? My copy (a photocopy) has only a black-and-white photo, which is not too useful.
Chris