Establishing species and species boundaries in Sabellastarte Krøyer, 1856 (Annelida: Sabellidae): an integrative approach

Abstract

Sabellastarte Krøyer, 1856 (Sabellidae), a morphologically homogeneous group distributed in warm and temperate coasts of the Indo-Pacific and Caribbean Sea, is characterized by the presence of a unique combination of features. To date, the genus comprises eight species, but morphological characters traditionally used in diagnostics have shown intra-specific variability, making species boundaries and distributions unclear. The present study constitutes the first attempt to test the monophyly of Sabellastarte and its relationships to other sabellid genera by combining molecular (COI and 16S) and morphological data. Results include placement of a clade containing Stylomma, Sabella, Branchiomma and Bispira as the sister group to Sabellastarte. Phylogenetic analyses and genetic divergence among specimens from several localities around the world indicate the presence of at least six lineages within Sabellastarte. In the context of a discussion of species boundaries and diagnostic features, the distribution of some of those lineages can be explained by the presence of cryptic species and potential introductions.

Sabellidae (Annelida) from the Faro coastal lake (Messina, Ionian Sea), with the first record of the invasive species Branchiomma bairdi along the Italian coast

“…This investigation highlights the intraspecific variability for some of them. Intraspecific variability has already been reported in other sabellids as the main bias in establishment of species boundaries (Capa et al, 2010). Small-scale spatial distribution and ecological notes for each species are also reported.…”

“…This has already been pointed out for the Sabellastarte genus by Capa et al (2010), who state that some of the features that have traditionally been used to distinguish species change during development, growth and regeneration, and should not be considered as diagnostic. These include the number of chaetae in a fascicle and the presence of spiralling radioles of the crown lobes, which are both known to vary with age.…”

A taxonomic guide to the fanworms (Sabellidae, Annelida) of Lizard Island, Great Barrier Reef, Australia, including new species and new records

“…Sabellids or feather-duster worms are characterised, among other features, by an often colourful radiolar crown emerging from the tube which they inhabit, and are well appreciated among divers and aquarium lovers as some species are also exploited for ornamental purposes (Capa et al 2010;Murray et al 2013). Sabellidae is one of the most diverse and ubiquitous polychaete families with over 400 nominal species described to date, currently grouped in 39 genera .…”

Kimberley marine biota. Historical data: polychaetes (Annelida)

“…However, the presentation of the data in this way allows an assessment of which locations in the Kimberley have been surveyed for polychaetes, and provide an indication of the available data. Current integrative studies, incorporating genetic data with the morphological information, are demonstrating that some of the species previously considered widespread are in fact a complex of sibling species, increasing the diversity of known polychaete fauna in Australia and the Kimberley (see for example Capa et al 2010).…”

“…While polychaete collections were historically preserved in formalin, contemporary collection practice now routinely preserves material in ethanol to enable subsequent genetic studies, which are changing our taxonomic concepts -see for example Capa et al (2010Capa et al ( , 2013 and Wei et al (2013). Such studies are expected to continue and the contemporary surveys underway (2009)(2010)(2011)(2012)(2013)(2014) in the Project Area are undertaking such practices.…”