Exogene orsted, 1845 (Annelida: Syllidae: Exogoninae) from Brazilian oceanic islands, with description of a new species and notes on possible hidden diversity in the genus

Valuable efforts have been made to describe the diversity of Syllidae Grube, 1850 in Brazilian waters, but only recently, taxonomic accounts of the family from oceanic islands began to be published. Here we reported five species of Exogone orsted, 1845 from Rocas Atoll, Fernando de Noronha and Trindade Islands. Exogone rocassp. nov. is described and Exogone simplex Hartmann-Schroder, 1960 (described and illustrated), Exogene africana Hartmann-Schroder, 1974, Exogene breviantennata Hartmann-Schroder, 1959, and Exogene naidinoides Westheide, 1974 are reported for the first time from Brazilian oceanic islands. Finally, we make considerations about the use of only morphology to identify these species, the doubts on the species records and the possible presence of sibling species under their currently reported distribution range.