Alright to get things started, andersons and axolotols are famous because they remain in their juvenile aquatic stage their whole life, something in them tells them to remain an aquatic salamander. If the mud puppy you are going to buy is a Ambystoma tigrinum or a tiger salmander then it will morph on its own no need to coax it, but as soon as you see the gills start to shrink maybe lower the water level and add a land area. So if you are looking for a salamander that stays in a larval state go for an axolotl just look em up they are pretty sweet looking!

-Nick