Echyridella aucklandica

Echyridella aucklandica

Nationally Vulnerable (NZ TCS)[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Unionida
Family: Unionidae
Genus: Echyridella
Species:
E. aucklandica
Binomial name
Echyridella aucklandica
(Gray, 1843)
Synonyms[2]
  • Cucumerunio websteri (C. T. Simpson, 1902)
  • Cucumerunio websteri delli McMichael & Hiscock, 1958
  • Diplodon (Hyridella) menziesi lucasi Suter, 1905
  • Diplodon menziesii lucasi Suter, 1905
  • Diplodon websteri C. T. Simpson, 1902
  • Echyridella lucasi (Suter, 1905)
  • Hyridella aucklandica (J. E. Gray, 1843)
  • Unio aucklandicus J. E. Gray, 1843

Echyridella aucklandica is a species of freshwater mussel endemic to New Zealand. E. aucklandica is an aquatic bivalve mollusc in the family Unionidae, the river mussels.

Description

Echyridella aucklandica was first described by John Edward Gray in 1843 and given the name Unio aucklandicus.[2] It was described again by American malacologist Charles Torrey Simpson in 1902, who used the name Diplodon websteri.[3] Simpson's original text (the type description) reads as follows:

Diplodon websteri Simpson.

Shell long, rhomboid, compressed or subcompressed, inequilateral; beaks subcompressed, pointed, their sculpture apparently a few irregular lachrymose nodules arranged in a somewhat radial pattern; surface with uneven growth lines and impressed rest marks, sculptured throughout with lachrymose nodules which are often V-shaped, those along the upper part of the low posterior ridge slightly knobbed; epidermis dark olive green, clouded with lighter green, rather dull; pseudo-cardinals small, subcompressed, granulose, two in each valve ; laterals straight, two in the left valve, one in the right; muscle scars small, shallow and irregular; nacre bluish,

lurid purple near and in the beak cavities, thicker in front.

The length of the shell is 62–81 mm. The height of the shell is 32–39 mm. The width of the shell is 14–20 mm.[3][4]

Distribution

Echyridella aucklandica is found in two separate locations, Southland and the lower North Island. This broken distribution may have come about due to transportation by Māori.[5] It inhabits lakes and streams.[4]

Ecology

Like other unionids, E. aucklandica has a complex life-cycle characterised by a parasitic larval stage called glochidia that require a fish host to metamorphose into juveniles.[6] Echyridella aucklandica glochidia attach themselves exclusively to the New Zealand smelt, unlike the more common Echyridella menziesii, which generalises to many different host species.[7][6]

References

  1. ^ Grainger, Natasha; Collier, Kevin; Hitchmough, Rod; Harding, Jon; Smith, Brian; Sutherland, Darin (May 2014). Conservation status of New Zealand freshwater invertebrates, 2013 (PDF). Wellington, New Zealand: Department of Conservation. p. 15. ISBN 9780478150155. Retrieved 24 June 2016.
  2. ^ a b "Echyridella aucklandica (J. E. Gray, 1843)". WoRMS. World Register of Marine Species. Retrieved 26 May 2023.
  3. ^ a b Simpson C. T. (1902) "A new naiad from New Zealand". Nautilus 16(3): 30.
  4. ^ a b Powell A. W. B., New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
  5. ^ Vennell, Robert (5 October 2022). Secrets of the Sea: The Story of New Zealand's Native Sea Creatures. HarperCollins Publishers. pp. 38–43. ISBN 978-1-77554-179-0. LCCN 2021388548. Wikidata Q114871191.
  6. ^ a b Melchior, Michéle (2021). Partitioning along reproductive niche dimensions in sympatric New Zealand freshwater bivalve species (Thesis thesis). The University of Waikato.
  7. ^ Melchior, Michele; Squires, Nicole J; Clearwater, Susan J; Collier, Kevin J (2023). "Discovery of a host fish species for the threatened New Zealand freshwater mussel Echyridella aucklandica (Bivalvia: Unionida: Hyriidae)". New Zealand Journal of Marine and Freshwater Research. 57 (1): 152–159. doi:10.1080/00288330.2021.1963290. ISSN 0028-8330.