In vitro larvae metamorphosis of a New Zealand native freshwater mussel (Bivalvia: Unionida: Hyriidae) Echyridella menziesii

ABSTRACT

New Zealand freshwater mussels are in decline. To support their restoration, existing methods developed for the laboratory transformation of other mussel species were trialled and adapted to establish a method for the successful in vitro propagation of a New Zealand freshwater mussel species, Echyridella menziesii. This paper provides details of the methods and the requirements for metamorphosis including products and equipment, the selection and collection of quality glochidia, procedures to reduce bacterial and fungal infection, the collection and use of fish plasma and mammalian sera, incubation densities and duration and the transition to water. This is the first documented case of successful in vitro metamorphosis, from glochidia to juvenile, of a native New Zealand freshwater mussel which has implications for the conservation of Australasian species.

KEYWORDS:

• Glochidia
• kākahi
• propagation
• transformation
• artificial culture
• bivalve restoration

Acknowledgments

The authors would like to thank Uthaiwan Kovitvadhi and Satit Kovitvadhi for hosting KT and SC, generously teaching in vitro culturing techniques at the Kasetsart University, Bangkok, and continuing to provide advice. We also thank Akkarasiri Sangsawang for being a part of that visit and for subsequently working in our New Zealand laboratory and contributing to our successful progress. We thank Shannan Bell and Anathea Albert for their technical contribution to this project, Morgan Kern for her advice on media transfers, and Deborah Hofstra (NIWA) and Michele Melchoir (University of Waikato) for their valuable feedback on the manuscript. Finally, we acknowledge the journal editors and Manuel Lopes-Lima and an anonymous reviewer for their comments which helped improve the manuscript. This research was funded by the New Zealand Ministry of Innovation and Employment (MBIE) grant to NIWA for the ‘Cultural Keystone Species: Co-management and restoration of our freshwater taonga species’ Program (No. C01X1616) and ‘Freshwater bioremediation using native mussels’ (No. C01X1815).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the New Zealand Ministry of Business, Innovation and Employment (MBIE) grant to NIWA for the ‘Cultural Keystone Species: Co-management and restoration of our freshwater taonga species’ Programme (No. C01X1616) and ‘Freshwater bioremediation using native mussels’ (No. C01X1815).