Well adapted for life out of the water, this crab has evolved to retain water in its gill chamber which allows it to be outside of the water for nearly 3 days. This makes it one of the most semi-terrestrial shore-crabs. Females are sexually mature at 1 year, can carry 50,000 eggs and typically reproduce in the summer. They are reported to sometimes prey on their close relatives living on the mud flats, Hemigrapsus oregonensis (yellow shore crabs). The striped shore crab’s shell has little permeability, which aids in its ability to retain water and, therefore, enjoy a semi-terrestrial foraging range.