MARINE MAMMAL SCIENCE, 22(4): 979–984 (October 2006) C  2006 by the Society for Marine Mammalogy DOI: 10.1111/j.1748-7692.2006.00058.x EPIZOIC BARNACLES REMOVED FROM THE SKIN OF A HUMPBACK WHALE AFTER A PERIOD OF INTENSE SURFACE ACTIVITY FERNANDO F ´ ELIX Fundaci´ on Ecuatoriana para el Estudio de Mam´ ıferos Marinos (FEMM) P.O. Box 09-09-11905, Guayaquil, Ecuador E-mail: fernandofelix@femm.org BRITTANEY BEARSON Fundaci´ on Ecuatoriana para el Estudio de Mam´ ıferos Marinos (FEMM) P.O. Box 09-09-11905, Guayaquil, Ecuador and Oregon State University, Corvallis, Oregon 97331-2911, U.S.A. J ´ ESSICA FALCON ´ I Fundaci´ on Ecuatoriana para el Estudio de Mam´ ıferos Marinos (FEMM) P.O. Box 09-09-11905, Guayaquil, Ecuador Humpback whales (Megaptera novaeangliae) as well as other slow-moving Mysticetes such as gray (Eschrichtius robustus) and right whales (Eubalaena spp) are commonly infested with various epizoonts and ectoparasites (Fertl 2002). Humpbacks are par- ticularly prone to infestation by two species of sessile crustaceans (Cirripedia), the acorn barnacles Coronula diadema and Coronula reginae. These acorn barnacles are used as settlement substrate by the stalked barnacles Conchoderma auritum and Conchoderma virgatum (Clarke 1966, Dawbin 1988, Fertl 2002). Although none of these barnacles are true ectoparasites as they do not feed on whale skin or body fluids, they could become abundant enough to increase drag and affect hydrodynamics. According to Slijper (1979), older whales carry more barnacles than younger animals. In addition, animals with reduced movement due to sickness become more heavily infested with ectoparasites and epizoots (Fertl 2002). One account reported a humpback whale with more than 1,000 lb (454 kg) of barnacles attached to its body (Slijper 1979). Acorn barnacles attach to humpback whales as cyprid larvae by means of their cement glands (Schmitt 1965). The more abundant C. diadema does not embed in 979