Morphological and molecular analyses of Vaucheria section Piloboloideae (Xanthophyceae: Vaucheriaceae) indicate alternative species identities for broadly distributed taxa

ABSTRACT

The discovery of a previously unrecorded Vaucheria species in subtidal marine habitats in Western Australia has led to a review of species included in Vaucheria section Piloboloideae, a taxon that includes several problematic invasive species. Molecular analyses placed this species in a clade including the New Zealand Vaucheria aestuarii and additionally indicated conspecificity with specimens from the North Sea that have been previously regarded as invasive V. longicaulis. However, our molecular analyses from the Californian type locality of V. longicaulis have shown that the North Sea taxon is not that species. Instead, it belongs to V. aestuarii, previously described from New Zealand, now also discovered by us at the coast of Western Australia. The sequences from the type locality of V. longicaulis, however, match those of an unidentified Vaucheria, coincidentally also found in the North Sea, reported as Vaucheria sp., and also recently referred to V. aff. compacta from Svalbard in the Arctic. Our work provides a taxonomic framework for two widespread invasive species and a key to all known species of the section Piloboloideae.

KEYWORDS:

• Australia
• Invasive
• Vaucheria longicaulis
• Vaucheria aestuarii
• Yellow-green algae

ACKNOWLEDGEMENTS

Sincere thanks to Kerstin Wasson (Elkhorn Slough National Estuarine Research Reserve) and Phil Novis, who kindly provided Vaucheria from the type locality of V. longicaulis, and a portion of the type specimen of V. aestuarii, respectively. We also thank the staff of the Western Australian Herbarium for curatorial support, Trevor Bringloe for assistance with molecular work, and Phil Novis and Abishek Muralidhar for clarifying incorrect specimen data in Muralidhar et al. (2014).

DISCLOSURE STATEMENT

No potential conflicts of interest are reported by the authors(s).

Additional information

Funding

This work was supported by Australian Biological Resources Study (Activity ID 4-G046WSD) and the University of Melbourne’s Research Computing Services and the Petascale Campus Initiative.