Un nouveau copépode parasite de la cavité palléale d'un gastéropode bathyal dans le golfe de gascogne, Myzotheridion seguenziae gen. sp. nov.

A new species of parasitic Copepod from Mollusca representing the type of a new genus has been discovered in the Gulf of Biscay : Myzotheridion seguenziae gen. sp. n. This Copepod inhabits the mantle cavity of a bathyal Gastropod very common in the North of the Gulf of Biscay, between 1900 and 2250 m depth, Seguenzia carinata. The rate of parasitism, from more than 500 Gastropods, reaches as an average 7,l %. A few special morphological features have been recognised : presence of a plurilobate sucker for the female, reduction of thoracic and abdominal segments for the male. The genus Myzotheridion, closely related to the genus Endocheres, probably belongs to the family Ventriculinidae (Dichelesthioidea), but its morphological features corroborate the heterogeneity of this family. [NOT CONTROLLED OCR]