Cambarus aculabrum is a rare species of crayfish known by the common name Benton cave crayfish. It is native to Arkansas in the United States, where it is known from only four locations. It is a federally listed endangered species of the United States.This crayfish was first described to science as a new species in 1987. It is about 48 millimeters (1.8 inches) long. A troglobite, it lacks pigment, making it white in color, it and has only rudimentary eyes.