While several species of mud crab can be present in any one location, it appears
common that one species makes up a dominant percentage of the overall crab
population, for example in Aklan, the Philippines, S. olivacea comprised 95 percent of
the mud crab population, with 2 other species present in the same area.
As mud crabs appear to have an interdependent relationship with mangrove forests,
the loss of mangroves, for whatever reason, will typically be followed by lower crab
catches. However, mud crabs are found in estuaries without mangroves, so they are not
essential for their colonization or survival.