Pregnant females carry the eggs externally as a sponge beneath their pleiopods. As the eggs develop, the females return to the high salinity areas where the eggs undergo the final maturation and the zoea are released. The entire life cycle following the late megalopal stage is spent within the estuary. In general crabs are opportunisitic predators. Their diets may include a wide range of taxa including bivavles, crustacea and fish.
Diets vary with crab size.
Small crabs exploit thin-shelled bivalves and other invertebrates that are buried relatively shallowly in the sediments. Larger crabs can exploit thicker shelled bivalves and cannibalism is not uncommon. Thus, crabs may be keystone predators in the estuary, sensu Paine, possibly playing a dominant role in structuring benthic communities throughout its range. In turn crabs fall victim to several fish species including sciaenids and moronids . For example, recently concern has been expressed over the interaction between striped bass and blue Chesapeake Bay blue crabs.