Crangon species are found exclusively in the Northern Hemisphere, with most of the species occurring in the northern Pacific Ocean.[1] C. septemspinosa is the only species in the genus to occur in the north-western Atlantic Ocean, while in the north-eastern Atlantic, C. crangon and C. allmani occur.[1] With the exception of the important commercial species C. crangon, however, the distributions of Crangon species are poorly characterised.[1] The greater number of species in the Pacific Ocean is thought to indicate that the genus originated in the Pacific.[1]