The polychaete genus Laeonereis (Annelida, Nereididae) occurs over a broad geographic range and extends nearly across the entire Atlantic coast of America, from USA to Uruguay. Despite research efforts clarify its diversity systematics, mostly by morphological ecological evidence, there is still uncertainty, mainly concerning species culveri , which constitutes an old notorious case taxonomic a...

The family Nereididae includes more than 500 polychaete species described worldwide, and includes species common in many benthic environments, but some other species may tolerate freshwater or can even thrive in humid substrates in tropical forests. In estuarine environments, nereidid polychaetes can be abundant and relevant as a food source for resident or migratory birds. Laeonereis culveri (...

Three hundred and thirty two species of polychaetes belonging to 50 families are reported for Costa Rica based on previously published reports. In a few families, available material was re-examined and appropriate changes in species identifications were made. Only three species, (Glycera oxycephala Ehlers, 1887; Hemipodia pustulata (Friedrich 1956); and Scolepis (Scolepis) squamata (Miller, 180...

The nereidid polychaete genus Namalycastis Hartman, 1959 has been recorded almost exclusively in non-marine environments. This genus includes species having four pairs of tentacular cirri, and its species mainly differ by the relative size of dorsal cirri in posterior chaetigers. Namalycastis occulta n. sp. is described based upon non-mature and mature specimens collected in the intertidal from...