[EN] Juveniles and adult females of Genesis vulcanoctopusi gen. et sp. nov. (Copepoda: Harpacticoida) are described from the deepwater octopus Vulcanoctopus hydrothermalis, collected from a hydrothermal vent in the East Pacific Rise. The new genus is placed in the Tisbidae and is readily distinguishable from other Cholidyinae by the combination of body shape, structure of oral appendages and segmentation of legs 1-5. All stages were found embedded in the integument of the head and mantle of the cephalopod host, suggesting an endoparasitic copepodid phase. The generalized life cycle of cholidyinid harpacticoids is reinterpreted in the light of this discovery. Aspects of parasitism and pathological effects of G. vulcanoctopusi on the octopod host are discussed

[FR] Les juvéniles et les femelles adultes de Genesis vulcanoctopusi gen. et sp. nov. (Copepoda: Harpacticoida) sont décrits sur l'octopode Vulcanoctopus hydrothermalis, récolté sur un site hydrothermal de la ride du Pacifique est. Le nouveau genre est placé dans les Tisbidae et se distingue nettement des sutres Cholidyinae à la fois par la forme du corps, la structure des appendices oraux et la segmentation des pattes 1-5.

This work was funded by the URM 7 IFREMER and DORSALES Programme. One of us (PJL-G) acknowledges financial support for a visit to the Natural History Museum (London) under the EC-funded TMR Bioresource Large-Scale Facility Programme.

13 pages, 8 figures.

Peer reviewed