Systematic revision of Sabellariidae (Polychaeta) and their relationships with other polychaetes using morphological and DNA sequence data

Abstract

The affinities of honeycomb or sandcastle worms (Sabellariidae, Polychaeta) and other polychaetes are studied using morphological and DNA sequence data (18S rDNA, 28S rDNA, and EF-1 alpha). Maximum-parsimony analyses were performed including 20 terminals and 7155 aligned characters. The monophyly of Sabellariidae is confirmed and well supported and sister-group relationships with Spionida are suggested but only poorly supported. Phylogenetic relationships within Sabellariidae are also assessed for the first time, using morphological data. Maximum-parsimony analyses of 30 terminals and 31 characters were performed with and without weighting the less homoplasious characters. Implied weighting resolved polytomies recovered after non-weighting datasets and suggest that the established sabellariid subfamilies are not monophyletic and that the number of parathoracic segments is homoplastic. Instead, some opercular features and chaetal characters not often incorporated in descriptions are here shown to be phylogenetically informative and support some of the clades recovered. We provide a description of morphological features of sabellariid and previously related groups together with illustrations that will, we hope, be used as a baseline for further systematic and taxonomic studies in the group and as a framework for future molecular studies. Generic diagnoses and a description and a key to genera are provided.

Anterior sensory organs in Sabellariidae (Annelida)

“…We then used the sabellariid phylogeny by Capa et al. () to put our observations into a comparative context.…”

Sabellariidae from Lizard Island, Great Barrier Reef, including a new species of Lygdamis and notes on external morphology of the median organ

“…It has been reported as absent in members of the genera Gunnarea Johannson, 1927Mariansabellaria Kirtley, 1994, Neosabellaria Kirtley, 1994and Paraidanthyrsus Kirtley, 1994, Phragmatopoma (Fig. 10A-B) and some species of Sabellaria and present in the rest of sabellariids (e.g., Kirtley 1994;Capa et al 2012;Capa & Hutchings 2014). However, we now interpret it as absent in Idanthyrsus willora (contrary to Hutchings et al 2012, Fig.…”

“…This planktonic larva is provided with four parathoracic segments, simple (unbranched) feeding tentacles, nuchal hooks (with strongly bent sharp tips), and without limbations, operculum completely divided in two lobes, features that are characteristic for Gesaia species (Kirtley 1994;Capa et al 2012;Capa & Hutchings 2015). The paleae morphology, with straight and cylindrical outer and inner paleae, and paleae arrangement, with outer paleae forming a semicircle and the inner paleae in an almost straight line between opercular lobes, is also most similar to benthic stages of members of this genus.…”

Phylogeography of the reef‐building polychaetes of the genus Phragmatopoma in the western Atlantic Region

“…Systematics of the genus have been recently revised (Drake et al, 2007;Capa et al, 2012). Notwithstanding, the brief original descriptions for P. caudata and P. lapidosa and the disappearance of the type material led to uncertain taxonomic status.…”