look at a geosesarma species. They live totally away from brackish water and don't need it to reproduce. This is my male vampire crab and below are his babies
60%eco-earth, 40% sand substrate, Temp 78~82F, High humidity tank
A few plants including bromeliands, Java ferns, Mosses, riccia and anubias
20L tank with 1x65 CFL
Small shallow dishes for water
Feeds on flake food and hikari crab bites