World Register of Marine Species (WoRMS)
Schuchert, P.; Choong, H.; Galea, H.; Hoeksema, B.; Lindsay, D.; Manko, M.; Pica, D. (2026). World Hydrozoa Database. Pliobothrus symmetricus Pourtalès, 1868. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=117962 on 2026-08-25
Pourtalès, L.F. de. (1868). Contributions to the fauna of the Gulf Stream at great depths (2d series). Bulletin of the Museum of Comparative Zoology at Harvard College, in Cambridge. 1(7): 121-142.