Abstract:
Several records describe pseudostalked barnacles Xenobalanus globicipitis attached to killer whales Orcinus
orca, yet little is known of this association in Southern 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 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 is an additional means to distinguish
between these populations.
