New data on morphology and redescription of Aphotopontius mammillatus Humes, 1987 (Copepoda, Siphonostomatoida, Dirivultidae) from deep-sea hydrothermal vents in the eastern Pacific (Guaymas Basin)

Aphotopontius mammillatus Humes, 1987 associated with a vestimentiferan from a deep-sea hydrothermal vent in the Gulf of California (Guaymas Basin), 1993 m depth, is redescribed on the basis of new morphological data and reexamination of additional specimens from the type locality. About twenty morphological characteristics unknown for this species are described and discussed.