Nereididae (Annelida) phylogeny based on molecular data

Nereididae is one of Annelida’s most diverse and well-studied families; despite this, only recently have molecular approaches been used to access phylogenetic hypotheses within the family. At least two nereidid groups can be identified based on mitochondrial gene order; however, this type of molecular information is not available for most taxa, and relationships of subfamilies are still poorly understood. In the present study, we used nuclear and mitochondrial markers to evaluate relationships within Nereididae and verified hypotheses on subfamilies delineation and relationship. Our results suggest the paraphyletic status of Gymnonereidinae and Nereidinae, as well as some genera within these subfamilies. Despite this, a revision of these subfamilies delineation and diagnoses was presented to match current phylogenetic understanding of the group. We suggest reverting to the original definition of Gymnonereidinae to include only the genera originally proposed by Banse in 1977. Our results also support monophyly of a large group that can be defined by mitochondrial gene order. This group includes most taxa identified as Nereidinae, and therefore, we suggest that this feature should be used as diagnostic of the subfamily.