Taxonomic revision of the genus Exallopus Jumars, 1974 (Dorvilleidae: Annelida) with description of a new species from the Southwestern Atlantic Ocean

Exallopus Jumars, 1974 is a dorvilleid genus composed of five species and mainly characterized by the modified chaetae of the first parapodia and the morphology of its jaw apparatus. The analysis of the material deposited at the Smithsonian Institution (USNM), USA, and at the Museu de Diversidade Biológica (MDBio), Brazil, allowed the redescription of five species of the genus, based on their type and non type material E. blakei, E. cropion, E. intermedia, E. jumarsi and E. pentadiaphoros. The material stored in the MDBio collection represents the first record of Exallopus on the Brazilian coast (Southwest Atlantic Ocean), expanding the known distribution of E. blakei, E. cropion, E. pentadiaphoros and E. intermedia, while also revealing a new species of the genus, E. hilbigae sp. nov. The new species is characterized by the presence of modified simple and compound chaetae on the first five to seven parapodia, which are more robust, with the shaft and modified compound blades unfused. Finally, we also provide a dichotomous identification key for all known species within the genus. http://zoobank.org/urn:lsid:zoobank.org:pub:01AAF671-EC1A-4964-8376-A5F6187F8ED6