[2] The species is now only known from the northern Pacific Ocean where gray whales are found.

The gray whale was present in the northern Atlantic Ocean between the Late Pleistocene and recent times, and C. rhachianecti fossils have been found on a beach in the Netherlands, showing that the barnacle must also have been present.

[5] On the gray whale, the barnacles embed themselves deeply in the skin and are mostly clustered on the animal's head and back.

So common are these that an adult gray whale may be carrying several hundred pounds weight of barnacles and lice.

[2] Gray whales have been observed rubbing their bodies against pebbly seabeds in an apparent effort to rid themselves of attached organisms.