Abstract
Numerous invasive aquatic species introductions can be traced to the aquarium trade. Many potentially harmful aquarium species may be difficult to identify based on morphology alone. As such, some prohibited or invasive species may be available for purchase if they are mislabeled as species without restrictions. Here we compare molecular identifications to internet vendors’ identifications for accessions of a popular genus of aquarium plants that are difficult to distinguish morphologically (Myriophyllum; watermilfoils). Specifically, we identified the extensive mislabeling of M. heterophyllum—an invasive species in the northeastern and western US. Furthermore, genotypes of M. heterophyllum found in our aquarium survey have also been found in invasive populations, suggesting their potential introduction through escape from aquaria, water gardens, or nurseries. Two additional taxa were sold under incorrect names. Finally, our survey revealed that Myriophyllum taxa present in the aquarium trade generally have poorly known distributions and ecologies, and therefore their invasive potential is unknown. Our study confirms that molecular identification methods can provide a valuable tool to survey commercial pathways for potentially harmful species that are otherwise difficult to identify.
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Notes
Vendors were located in Florida, Ohio, Pennsylvania, Michigan, Wisconsin, Minnesota, South Dakota, and Arizona.
ITS and trnK 5′ alignments are provided as supplementary material.
Comparison of our ITS sequences to those by Moody and Les (2010) is available as supplementary material.
Comparison of our trnK 5′ sequences to those by Moody and Les (2010) is available as supplementary material.
Comparison of the phylogenetic positions of M. sp. red1 and M. sp. red2 to the vendor species names can be seen in Fig. 1.
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Acknowledgments
We thank Caleb James, Heather Schellie, Heather Hayward, Patricia Phillips, and Matthew Zuellig for laboratory assistance. Colleen Lyon provided valuable assistance obtaining early taxonomic treatments of Myriophyllum. Three anonymous reviewers provided helpful comments that improved the manuscript. We also thank Ann Bove, Jen Parsons, and Amy Smagula for helpful conversations throughout the development of this project, and the Thum lab group for comments on an early draft of this manuscript. Funding for this project was provided by National Science Foundation grants to RAT (DEB-0918553 and DBI-0922591), including a National Science Foundation Research Experiences for Undergraduate supplement for ATM.
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Thum, R.A., Mercer, A.T. & Wcisel, D.J. Loopholes in the regulation of invasive species: genetic identifications identify mislabeling of prohibited aquarium plants. Biol Invasions 14, 929–937 (2012). https://doi.org/10.1007/s10530-011-0130-8
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DOI: https://doi.org/10.1007/s10530-011-0130-8