New records of non-indigenous Branchiomma and Parasabella species (Sabellidae: Annelida) in South Australia highlight the continuing challenges for sabellid taxonomy

ABSTRACT

Sabellid fanworms (Sabellidae: Annelida) and particularly species of Branchiomma and Parasabella are difficult to discriminate due to a lack of unambiguous diagnostic characters and high intraspecific morphological plasticity. We studied specimens identified as Branchiomma and Parasabella from a marina in South Australia. Examination of morphological features alone failed to resolve the unambiguous identification of specimens to species. Therefore, two DNA markers, the nuclear internal transcribed spacer (ITS) and the mitochondrial cytochrome c oxidase I (cox1), were sequenced. Phylogenetic analyses and genetic distances were performed for each DNA marker, including Branchiomma and Parasabella sequences available in GenBank. Molecular analyses indicate that specimens belong to species that have previously been reported as cryptogenic and occurring in several worldwide harbour environments, but whose identity is still unsettled. A discussion about the relevance of several sources of information for species delineation, and the importance of taxonomy, is provided.

KEYWORDS:

• polychaetes
• fanworms
• morphology
• molecular taxonomy
• integrative taxonomy
• introduced species
• non-indigenous
• translocations

Acknowledgements

Thanks to Emma Johnston for supervisory support, Alex Chalupa (Biosecurity South Australia) for help in the field; Eunice Wong for assistance with DNA extraction; Hannelore Paxton (Macquarie University) for translating German texts; Sue Lindsay (Macquarie University) for expertise with the scanning electron microscope; and Blue Sky Marine and North Haven Marine for wharf access.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

This research was funded by a grant from the Evolution & Ecology Research Centre of the University of New South Wales, Australia. Funding was provided by the Ramón y Cajal programme (RYC-2016-20799) funded by Spanish MINECO, Agencia Estatal de Investigación, Comunidad Autónoma de las Islas Baleares, and the European Social Fund to MC.