Evidence of new species of Haematoloechus (Platyhelminthes: Digenea) using partial cox1 sequences

Abstract

Background and aims. Haematoloechus, digeneans parasites of amphibians, is a species-rich genus with more than 50 species around the globe. Establishing an accurate taxonomy for this group has been difficult due to high intraspecific variability. Nuclear DNA sequences have given independent information about species validity and phylogeny of the group. Materials and methods. In this paper, I test the performance of partial sequences of the mitochondrial cytochrome c oxidase subunit I (cox1) gene in the differentiation of recognized species of the genus and in the detection of potential new taxa. Samples from 13 nominal species were sequenced, plus four samples that could not be assigned to any described species based on morphology. Results. Parsimony analysis of the amplified 360 bp fragment resulted in six most parsimonious trees showing the same grouping of samples, differing in the samples' arrangement within those groups. All 13 species were recovered on the trees, and five potential new species are shown. Conclusion. Additional sampling and sequencing is necessary to support this hypothesis, but with this preliminary information the search for diagnostic characters that allow the description of the new taxa is less difficult.

Keywords::

• Digenea
• Haematoloechus
• Mexico
• cox1 sequences

Acknowledgements

The author deeply acknowledge Dan Brooks, Robert Bourgat, Valerie McKenzie, David Green, and Anindo Choudhury for donation of specimens; and Ma Antonieta Arizmendi, Rosario Mata, Elisa Cabrera, Elizabeth Martínez, Laura Paredes, Alejandro Oceguera, Rogelio Rosas, Agustín Jiménez, Ulises Razo, Gerardo Pérez, John Campbell, Eric Smith, Edmundo Pérez, and Alejandro Zaldívar for their help in field collections. Special thanks to Laura Márquez (IBUNAM) for her help in the sequencing of samples, and Luis García (CNHE), Erik Hoberg and Pat Pillitt (USNPC), and Scott Gardner (HWML) for the loan of specimens. This study was partially funded by CONACYT project 54475 to V.L.-R. and NSF grant DEB01613802 to Jonathan Campbell (University of Texas) and V.L.-R.

Declarations of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.