New Zealand freshwater mussel

New Zealand freshwater mussel
Echyridella menziesii (Dieffenbach, 1843) - Naturalis Biodiversity Center - ZMA.MOLL.213841
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Subclass:	Paleoheterodonta
Order:	Unionoida
Family:	Unionidae
Genus:	Echyridella
Species:	E. menziesi
Binomial name
Echyridella menziesi (Gray, 1843)[1]

The New Zealand freshwater mussel, scientific name Echyridella menziesi, or kākahi, is a species of freshwater mussel, an aquatic bivalve mollusc in the family Unionidae, the river mussels.

They were an important food source for the Māori,^[2] but like many freshwater mussels worldwide, are now endangered by pollution and eutrophication of rivers, and the introduction of new species of fish^[3] leading to actions via the Treaty of Waitangi claims process.^[4]

Distribution

Formerly common in lakes and streams around New Zealand.^[5]

Life cycle

Its reproductive cycle is typical of other freshwater mussels, requiring a host fish on which its larvae (glochidia) parasitize and metamorphose into juvenile mussels - most commonly the Koaro (Galaxias brevipinnis)^[6][7]

References

1. "Echyridella (Echyridella) menziesi (Gray, 1843) "
2. "Resource Management Issues of Significance to Iwi"
3. "The kakahi (Hyridella menziesi) in a general framework of lake health", 2008, Joseph Butterworth (MS thesis)
4. "Muriwhenua Fisheries Claim / SOE Claim", Waitangi Tribunal
5. "Freshwater mussel", Te Ara website
6. "Decline of the kakahi - identifying cause and effect", NIWA, Water & Atmosphere › Vol.10 No.4 - December 2002
7. "Kākāhi - the mysterious freshwater mussel", Greater Wellington Regional Council website

Bibliography

• Powell A. W. B., New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
• Manual of the New Zealand mollusca, 1913, Henry Suter
• Spencer, H.G., R.C. Willan, B. Marshall & T.J. Murray. 2011. Checklist of the Recent Mollusca recorded from the New Zealand Exclusive Economic Zone.