Hi! Tim.
It is hard to tell species on this picture and this specimen. I think I need to see the head shape on different angle, do you have more pictures?
I think I know why you wonder what is it. it is because it lacks of the point edges which the wenxianensis usually has on it's back head, but the body length seems too long for asperrimus, right?
In my opinion,I think it is wenxianensis. It is because I know the dealer who sell the wenxianensis shipment to Japan and I know if it is asperrimus, he will charge lot more money for it and the shop in Japan will put it in a different tank with different price tag than the wenxianensis.
However, it is just my opinion, I could be wrong. I think more pictures will help identify the specimen better.
Tylototriton is fun to work with ..... as long as you don't have hundreds of them....hahahaaaa