Echyridella menziesii

Echyridella menziesii, the New Zealand freshwater mussel, also known by its Māori names kākahi, kāeo, and torewai, is a species of freshwater mussel endemic to New Zealand. E. menziesii is an aquatic bivalve mollusc in the family Unionidae, the river mussels.

They were an important food source for the Māori, but like many freshwater mussels worldwide, are now endangered by pollution and eutrophication of rivers, and the introduction of new species of fish leading to actions via the Treaty of Waitangi claims process.

It is one of three species of native freshwater mussels identified in New Zealand, the others being Echyridella aucklandica and Echyridella onekaka.