Not valid. Adult female originally reported from the Sei whale Balaenoptera borealis off Chile. Also on the sei whale, Japan (redescribed by Wilson 1917). Found on the same hosts, in the same localities and falls easily within the morphological variability range of P. balaenoptera. Synonym of P. balaenoptera (Hogans 1987); accepted as P. balaenoptera (Walter & Boxshall 2015).