Pseudostalked barnacles Xenobalanus globicipitis attached to killer whales Orcinus orca in South African waters

Several records describe pseudostalked barnacles Xenobalanus globicipitis attached to killer whales Orcinus orca, yet little is known of this association in South African waters. Here we describe Xenobalanus prevalence on killer whales in South African waters and assemble previous records. Killer whales were photographed opportunistically between July and September 2013. Sex and age class were determined, and if Xenobalanus were present, attachment site and colony size were noted. A prevalence of 50 % was recorded, with barnacles most commonly observed on the dorsal fin and tail flukes. The high prevalence of Xenobalanus on killer whales in South African waters and lack thereof on killer whales at Marion Island implies that these are separate populations, and thus we suggest Xenobalanus prevalence as an additional means to distinguish between these populations.