Newts and Salamanders are a minority at "la ferme tropicale". They prefer reptiles...
For Newts and Salamanders, the better is ask to a seller, they have more animals in backroom than in the shop.
But now they have nothing of interest.
The "Jardin des plantes" ("muséum national d'histoire naturel") is nice. There are "la ménagerie", "la galerie de l'évolution", ...
It's stupid, I was in course here.... But I'm not in Paris this week end.