Crangon franciscorum is a species of shrimp in the Crangonidae family which is endemic to the brackish estuaries of California, and found from Puget Sound in the north to San Diego, California in the south. The species is especially abundant in San Francisco Bay, despite population fluctuations due to environmental stresses. Its common names include bay shrimp, sand shrimp, common shrimp, grass shrimp, black shrimp, California shrimp and black tailed shrimp. The species has been commercially fished from 1869 to the present.