Diopatra tuberculantennata, a new species of Onuphidae (Polychaeta) from Belize with a key to onuphids from the Caribbean Sea

A new species of the genus Diopatra Audouin & Milne-Edwards, 1833 from the intertidal zone in the vicinity of the Smithsonian field station (Carrie Bow Cay, Belize) is described. Diopatra tuberculantennata sp. nov. is identifiable by a combination of characters such as the presence of large lateral projections on both palpophores and antennophores, bidentate pseudocompound hooks with moderately long pointed hoods in the first five chaetigers, eyespots on the prostomium, nuchal organs forming almost a circle and very large sensory papillae on antennostyles and frontal and upper lips. Five 28-chaetiger juveniles were found inside the parental tube of one specimen. A pattern of anterior segment regeneration is described based on 12 specimens. A key for 20 species of onuphids known from the Caribbean Sea with the notes on their distribution is provided.