A new species of Streblosoma Sars, 1872 (Polychaeta, Terebellidae, Thelepodinae) from Brazil, with comments on Streblosoma oligobranchiatum Nogueira & Amaral, 2001

A new species of Streblosoma is described and the diagnosis of S. oligobranchiatum is emended, based on material collected on intertidal rocky shores along the State of São Paulo, Brazil, associated with algae, sponges, ascidians and other sedentary polychaetes. Streblosoma porchatensis n. sp. is characterised by the C-shaped arrangement of uncini from posterior thorax, numerous branchial filaments, some inserted laterally from the level of notopodia on segment 2, and by the morphology of uncini. The diagnosis of S. oligobranchiatum is emended to allow for variation in the number of branchial filaments and dental formula of uncini. Both species are compared with the closest congeners and some comments are made on the relationships within the group.