Its spinal column is contains 60–64 vertebra and its long lateral line (up to 84% the total length) helps to distinguish it from its relative, Bassogigas walkeri.

[2] B. gillii is found throughout the Indian and west Pacific Oceans from the tip of South Africa to New Caledonia including Madagascar.

[3] It is also found in the western Atlantic Ocean, though not the eastern, and is known from the United States, Bahamas, Cuba and Brazil.

[3] Other important areas where B. gillii can be found include the Gulf of Mexico, Bear Seamount and Agulhas Current.

[4][2] It can general be found living on or near the bottom at depths between 637 and 2239 meters.