Goose barnacle (Lepas australis) infestation of the Subantarctic fur seal (Arctocephalus tropicalis)

Abstract

Goose barnacle infestations (Lepas australis) were found on the pelage of two female  Subantarctic fur seals (Arctocephalus tropicalis) at Gough Island in the South Atlantic. The infested females were both relatively old at 11 and 15 years of age. We suggest that females might be more prone to infestation than males and that infestation is more common in the older age groups. One of the females was postreproductive and the other had lost its pup of the season, consequently they might have stayed longer at sea after settlement of the goose barnacles and prior to hauling out, than females with pups.  Attached to the guard hairs of the seal, the barnacles were clogged with underfur fibres, making it impossible for them to feed, leading to emaciation. A possible explanation for the clogging is that the seals had begun to moult.

Key words Subantarctic fur seal, Arctocephalus tropicalis, goose barnacle, Lepas australis, infestation