Distinct differences have been reported for the habitat preferences of S. paramamosain
of different sizes. Small crablets (carapace width [CW] 0.5 cm) settle on the outer
edge of mangroves, gradually moving deeper into the forests living on the surface of
mangroves (CW 1.5 cm), while larger crabs dig burrows or live in the subtidal zone
migrating in to feed in the mangroves at high tide (CW 4.5 cm), with the main adult
crab population living subtidally, offshore (CW 12.5 cm). The boundary between the
mangroves and mud crab flats is identified as an area that can support higher densities
of crabs.