Phylogeographic structure and historical demography of tarakihi (Nemadactylus macropterus) and king tarakihi (Nemadactylus n.sp.) in New Zealand

ABSTRACT

Tarakihi (Nemadactylus macropterus) is a demersal fish that supports valuable commercial, recreational, and customary fisheries in New Zealand. However, little is known about its stock structure. The population genetic structure, genetic diversity, and demographic history of N. macropterus were investigated using the hypervariable region one of the mitochondrial control region. 370 samples from 14 locations around New Zealand were collected. While weak genetic breaks were detected between Hawke’s Bay and East Northland and between the west and east coasts of South Island, no clear genetic structure was detected for the overall New Zealand area (Ф_ST = 0.002, P = 0.18), indicative of a panmictic genetic structure. N. macropterus display a high level of genetic diversity and appear to have a historically large and stable population with a long evolutionary history. Bayesian skyline analysis indicates that the historic population has gone through two expansions, likely caused by repeated glacial cycles during the second half of the Pleistocene. The addition of 15 king tarakihi samples (Nemadactylus n.sp.) collected from the Three Kings Islands showed a clear genetic differentiation between the two morphotypes. These findings can inform the future management of N. macropterus and N. n.sp. to ensure a sustainable harvest.

KEYWORDS:

• Population genetics
• stock structure
• mtDNA control region
• fisheries management
• teleost
• tarakihi
• king tarakihi
• demography

Acknowledgements

The authors thank Cameron Walsh (Stock Monitoring Services Limited) and the skippers and fishing companies for their assistance with the collection of specimens, including Salvatore Zame and Matt Howden (Gisborne Fisheries), Rick Burch and Andy Claudatos (Star Fish Supply), Curly Brown and Keith Mawson (Egmont Seafoods), Elisha Yahel, Richard Evans, Luke Fisken, Sam Hayes, Ben Turner, Kevin Saunders, Phil Clow, Craig Davidson, and William Macnicol (Moana New Zealand), Marcus D’Esposito and Rick Parker (Hawke’s Bay Seafoods), Tony Threadwell, Andrew Stark and Diane Payne (United Fisheries), Dion Irons, Tony Roach, and Ant Smith (Talley’s Seafood), Mike Williams (Wellington Trawling), Peter Young (Cindy Hardy Fiordland samples), and Jono (Cook Strait Fishing Charters). The authors are grateful for advice and assistance from the Removing Fisheries Juvenile Habitat Bottleneck Technical Advisory group, and in particular, they wish to acknowledge the support and consultation from Laws Lawson (Te Ohu Kaimoana), Jeremy Helson (Fisheries Inshore New Zealand), and Carol Scott (Southern Inshore Fisheries Management Company Limited). The authors also thank Mark Fenwick, Rob Stewart, and Dean Stotter (National Institute of Water and Atmospheric Research Limited) and John Van der Sman (Wellington University Coastal Ecology Laboratory) for providing us with the necessary logistics to process the samples. The authors thank Bianca Wohlers and Noémie Valenza-Troubat for providing useful feedback and edits to the manuscript and Tom Oosting for sharing some R scripts. CRediT authorship contribution statement: Yvan Papa: Conceptualisation, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data Curation, Writing – Original Draft, Writing – Review & Editing, Visualisation. Alexander G. Halliwell: Conceptualisation, Methodology, Software, Formal analysis, Investigation, Resources, Writing – Original Draft. Mark A. Morrison: Conceptualisation, Resources, Data Curation, Writing – Review & Editing, Supervision, Project administration, Funding acquisition. Maren Wellenreuther: Writing – Review & Editing, Supervision. Peter A. Ritchie: Conceptualisation, Resources, Writing – Review & Editing, Supervision, Project administration, Funding acquisition.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

DNA sequences have been submitted to GenBank under accession numbers MW147766 – MW148150. DNA sequence alignments are available on Figshare (DOI: 10.6084/m9.figshare.13317128 and 10.6084/m9.figshare.13317131). All R scripts used in the analyses are openly available on GitHub at https://github.com/yvanpapa/tarakihi_NZ_population_genetics.

Additional information

Funding

This work was supported by the New Zealand Ministry of Business, Innovation and Employment Endeavour Fund research programme "Juvenile fish habitat bottlenecks" [grant number CO1X1618] and by a Victoria University of Wellington Doctoral Scholarship.