The genus Branchamphinome Hartman, 1967 is a moderately understood genus of Amphinomidae that differs morphologically from most other genera in the form of its chevron-shaped caruncle and the presence of branchiae from chaetiger 1. Branchamphinome is presently represented by two deep-water species: B. antarctica, described from the Southern Ocean and B. islandica, from Iceland. We describe a new species of Branchamphinome from shallow South-west Atlantic waters, coast of Brazil. The new taxon revealed the surprising presence of notopodial hooks in chaetiger 1, which was subsequently also found to be present in the lectotype of B. antarctica. Both the genus and Hartman's species are emended to include this morphological feature. Historically, the presence of notopodial hooks has long been considered a diagnostic character for the genus Paramphinome, particularly when distinguishing Paramphinome from Linopherus. Branchamphinome tropicalis sp. nov. was found inhabiting sand sediments at depths of 150 m and temperatures of 16–20°C. Branchamphinome tropicalis sp. nov. differs from its congeners by its characteristic and highly developed pigmentation pattern, shape of the caruncle, branchiae and disposition of prostomial eyes. This is the first report of this genus from shallow tropical waters.

Two species of Sabidius Strelzov, 1973 were collected during a benthic survey, from 10-3,000 m deep, in Espírito Santo Basin, off southeastern Brazilian coast. Those species are S. cornatus (Hartman, 1965) and S. antennatus sp. nov. The genus Sabidius was monotypic until the present study, in which a new species is proposed, together with a redescription of the type species, with expansion of the geographic distribution of the genus and of the type species. The diagnostic feature of the genus is the morphology of prostomium, with crested anterior margin. The main feature that differentiates the two species within the genus is the presence/absence of a median antenna, which is present in the new species described in the present study and absent in Sabidius cornatus.

Three new species of the Paraonidae genus Aricidea (Acmira) are described from the Southwestern Atlantic, East Brazilian Continental Shelf (from depths between 11 and 44 m) in the Espírito Santo Basin. The species Aricidea (Acmira) filamentosa sp. nov., Aricidea (Acmira) pearti sp. nov. and Aricidea (Acmira) bbkingi sp. nov. are clearly different from all known species in the genus through its chaetal morphology, number of branchiate chaetigers and shape of antenna. These three species were found in only a few sampling stations, geographically and bathymetrically restricted within a much wider sampled area.

Three new species of Levinsenia were collected during a benthic survey, from 10–3,000 m deep, in Espírito Santo Basin, off the southeastern Brazilian coast. These species are L. paivai sp. nov., L. blakei sp. nov. and L. lesliae sp. nov. Members of L. paivai sp. nov. are recognized by the presence of nine pairs of well-developed and heavily ciliated branchiae, those of L. blakei sp. nov. are characterized by the presence of three pairs of small branchiae, and those of L. lesliae sp. nov., by the absence of branchiae and presence of notopodial transitional chaetae. These new species are described herein and compared to the most similar congeners. These are the first new species of Levinsenia described from off the Brazilian coast.