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.