Abstract Spirobranchus are abundant and diverse serpulids in tropical regions, with three species reported in Brazil, which occurrence is questionable, due to their distant type localities. In the present work, we describe a new species of Spirobranchus from the Brazilian coast and report the other species of the genus occurring off Brazilian shoreline, based on specimens from different locations. Specimens were collected in the states of Alagoas, Rio de Janeiro, and Santa Catarina, sorted and analyzed under a stereoscopic microscope. Then, the animals were anesthetized and subsequently fixed and prepared for the scanning electron microscopy. Specimens from the Caribbean and other Brazilian states were loaned from Museu Nacional of Universidade Federal do Rio de Janeiro, Universidade Estadual do Rio de Janeiro and Universidade Federal de Alagoas. Morphological analyzes differentiated the three species and provided details of the morphology that can be used in the future taxonomy of the family. The species S. giganteus and S. tetraceros are more similar to each other, but can be readily separated based on the spiral radiolar crown in the former; S. minutus differs from the other species for the tube, operculum, and type of uncini. Spirobranchus lirianeae sp. nov. nests within S. kraussii-complex, with a concave operculum, absence of collar chaetae and paired compound eyes on the radioles, differing by being a solitary rather than a gregarious species, by the funnel-shaped operculum, fringed tonguelets and tube with single keel, distally pointed.

Abstract Species of Serpulidae are common on benthic and biofouling communities, occurring attached on both natural and artificial substrates. In this paper, Serpulids were collected from intertidal to subtidal areas, on rocky shore and suspended artificial plates in port areas. Herein we report three new records of serpulid species to the coast of Rio de Janeiro, Brazil. We also discuss the misidentification of Spirobranchus tetraceros, which was previously reported to the north of Rio de Janeiro.

Abstract Ophryotrocha is the most speciose genus within Dorvilleidae, with species occurring in a great variety of environments around the globe. In Brazil, records of Ophryotrocha are scarce and no specific identification is provided for any of the records. Herein we describe a new species of Dorvilleidae, Ophryotrocha zitae sp. nov. Adult and larval specimens were found in the axis of a fragment of the cold-water coral Lophelia pertusa, sampled off São Paulo’s coast, at a depth of 245 m. Both forms are described and illustrated. This new species resembles O. puerilis, O. adherens and O. eutrophila, but can be distinguished based on differences in its mandible and on chaetae shape and arrangement.