Panopeus herbstii is small, growing to about 4 cm, with black-tipped claws of unequal size.

Panopeus herbstii is found along the Atlantic coast of North America, from Boston, Massachusetts to Santa Catarina, Brazil and on Bermuda.

[1] It is the most common xanthid crab on the east coast of the United States.

[2] It is found on muddy bottoms, where it takes refuge under stones and shells or among sponges and weeds, but it is rarely seen in the open.

It feeds mainly on young clams, oysters, and periwinkles; it cracks open their shells with its strong claws.