DNA barcoding of morid cods reveals deep divergence in the antitropical Halargyreus johnsoni but little distinction between Antimora rostrata and Antimora microlepis

Abstract

Background and aims: DNA barcoding strongly suggests that specimens of the slender codling (Halargyreus johnsonii) from New Zealand and Tasmania belong to a different species to H. johnsonii reported from other areas.

Results: Sequence divergence between the two groups averaged 3.95%, much higher than within-group divergences of 0.03 and 0.02% for specimens, respectively, from New Zealand–Tasmania and from the North Pacific, Atlantic Ocean, and Southern Ocean.

Conclusion: Meristic data for specimens from New Zealand and from the Southern Ocean north of the Ross Sea support the conclusion of two species. DNA barcodes for two sister taxa, Antimora rostrata and Antimora microlepis, show low intra-species (0.3–0.06%) and inter-species (0.23%) divergence.

Keywords::

• Marine fish
• Halargyreus
• Antimora
• COI
• cryptic species

Acknowledgements

The authors are grateful to two anonymous referees for constructive comments on the manuscript. New Zealand Halargyreus and Antimora specimens were collected by one of the authors (P.M.) and Ross Sea specimens by two of the authors (P.M. and A.S.) aboard the NIWA Research vessel Tangaroa. Specimens from around Heard and McDonald Islands and from Macquarie Island were collected by Australian Fisheries Management Authority observers.

Declaration of interest: New Zealand authors were supported by research funded by the New Zealand Government under the New Zealand International Polar Year-Census of Antarctic Marine Life Project, and by the Ministry of Fisheries (project GDB200801), and gratefully acknowledge the Ministry of Fisheries Science Team and Ocean Survey 20/20 CAML Advisory Group (Land Information New Zealand, Ministry of Fisheries, Antarctica New Zealand, Ministry of Foreign Affairs and Trade, and National Institute of Water and Atmospheric Research Ltd). D.S. was supported by funding from the Alfred P. Sloan Foundation to MarBOL and by Genome Canada, through the Ontario Genomics Institute.