Capitellidae (Annelida: Polychaeta) from Coiba National Park, Pacific Coast of Panama, with a new species of the genus Amastigos

During a study carried out in Coiba National Park (Pacific coast of Panama), several samples were collected from various substrata: dead coral heads, tidal flats, intertidal boulders and subtidal coarse sands. The results of the study of these samples regarding the family Capitellidae (Annelida: Polychaeta) are presented in this paper. Nine species are reported. A new species belonging to the genus Amastigos is described; it can be distinguished from the rest of the species within the genus by the shape of both thoracic and abdominal chaetigers. Another species, Leiocapitella glabra is reported for the first time in the Panamanian Pacific. Some specimens belonging to the genus Dasybranchus and Leiocapitella are partially described and figured showing their interesting morphological features, however, due to their poor preservation they have not been assigned to any described species.