The effect of the mesoparasitic barnacle Anelasma on the development of reproductive organs of deep-sea squaloid sharks, Centroscyllium and Etmopterus

Specimens of the mesoparasitic barnacle, Anelasma, were found attached to s everal host deep-sea squaloid sharks, Centroscyllium fabricii from off Gree nland, Etmopterus princeps from the Canary Islands, and Etmopterus unicolor and Etmopterus granulosus from Three Kings Ridge and Louisville Ridge near New Zealand. One to three parasites were partially embedded in each host s hark in the head, mouth, bases of 1st and 2nd dorsal fins, pectoral and pel vic fins, caudal fin, abdomen or claspers. Testes and claspers of parasitiz ed mature-sized males were less developed than those of non-parasitized mat ure males. The ova of parasitized females of mature size were small and whi tish-yellow compared to the large yellow ova of non-parasitized mature fema les. The number of mature ova in a parasitized specimen was lower than expe cted in relation to a non-parasitized individual of the same size. Attachme nt of parasitic barnacles appeared to retard the development of reproductiv e organs of host sharks.