The Asian (Pacific) shore crab (Hemigrapsus sanguineus) is a crustacean also known as the Japanese shore crab or Pacific shore crab. It was probably brought from Asia to the United States in ballast water. When a ship's hold is empty, it is filled with ballast water to stabilize the vessel.

The first Asian shore crab was seen in 1988 in Cape May, N.J. By 2001, Pacific shore crabs colonized the East Coast, with populations located from New Hampshire to North Carolina. Crabs live in the sub-tidal zone where low-tide water is several feet deep.

The Asian crab is 2–3 in (5–7.7 cm) wide. Shell color is pink, green, brown, or purple. There are three spines on each side of the shell. The crab has two claws and bands of light and dark color on its six legs.

A female produces 56,000 eggs per clutch. Asian Pacific crabs haves three or four clutches per year. Other crabs produce one or two clutches annually.

At the start of the twenty-first century, there was concern about the possible relationship between the rapidly growing Asian crab population and the decline in native marine populations such as the lobster population in Long Island Sound.