Abstract

A whale barnacle, Cryptolepas rhachianecti (Dall), previously considered an obligate commensal for the gray whale, Eschrichtius robustus (Lilljeborg), infested white whales, Delphinapterus leucas (Pallas), housed in San Diego Bay. The infestation occurred annually between January and April in concert with the northward migration of the gray whale, and did not occur during years when the white whales were housed elsewhere during these months. Although initial infestation elicited no apparent skin response, after successive years of exposure, massive cellular proliferation in the adjacent epidermis resulted in ejection of barnacles from the whales within a few weeks. This increasing epidermal response and the invasion of inflammatory cells at the juncture of skin and barnacle shell is suggestive of an immune reaction to the barnacles. We have observed this phenomenon yearly for 18 years. Although we have occasionally treated the barnacle infestations with a zinc oxide-copper sulfate topical mixture, we have never observed significant damage to the whales by the barnacles. [a full paper has been accepted for publication in Bulletin of Marine Science and is scheduled to appear in January, 1997]