Alathyria pertexta wardi Iredale, 1943

Diagnostic features

A. pertexta differs from the other species of Alathyria in being less elongate (height/length ratio less than 56%). Two subspecies are recognised, with the shell of A. pertexta wardi differing from A. pertexta pertexta in its truncate posterior, a generally weaker hinge, a marked posterior ventral sinuation, and in its slight anterior dorsal excavation. Another subspecies, A. pertexta magnifica, occurs in Papua.

Classification

Alathyria pertexta wardi Iredale, 1943

Common name: Ward's freshwater mussel

Class Bivalvia

Infraclass Heteroconchia

Cohort Palaeoheterodonta

Order Unionida

Superfamily Unionoidea

Family Hyriidae

Subfamily Velesunioninae

Genus Alathyria Iredale, 1934

Original name: Quaesithyria wardi Iredale,1943. In Iredale, T. (1934). The freshwater mussels of Australia. Australian Zoologist 8: 57-78.

Type locality: Einasleigh River, Queensland.

State of taxonomy

The last major taxonomic revision of Australian freshwater mussels was conducted by McMichael & Hiscock (1958). Based on recent molecular results, Walker et al. (2014) suggested that a reassessment of Australian hyriids is needed.

Biology and ecology

Shallow burrower in sand or gravel. Suspension feeder. Although the life cycle of this taxon has not been reported, larvae (glochidia) are likely brooded in marsupia in the gills of females and, when released, become parasitic on fish gills or fins where they presumably undergo metamorphosis before dropping to the sediment as free-living juvenile mussels.

Distribution

Cape York and Gulf of Carpentaria rivers and streams, Queensland.

Another subspecies, Alathyria pertexta magnifica McMichael & Hiscock, 1958, occurs in Papua.

Further reading

Beesley, P. L., Ross, G. J. B. & Wells, A., Eds. (1998). Mollusca: The Southern Synthesis. Parts A & B. Melbourne, CSIRO Publishing.

Iredale, T. (1934). The freshwater mussels of Australia. Australian Zoologist 8: 57-78 pls 3-6.

Iredale, T. (1943). A basic list of the fresh water Mollusca of Australia. Australian Zoologist 10: 188-230.

Lamprell, K. & Healy, J. (1998). Bivalves of Australia, volume 2. Leiden, Backhuys Publishers.

McMichael, D. F. & Hiscock, I. D. (1958). A monograph of the freshwater mussels (Mollusca: Pelecypoda) of the Australian region. Australian Journal of Marine and Freshwater Research 9: 372-508.

Smith, B. J. & Kershaw, R. C. (1979). Field guide to the non-marine Molluscs of South-eastern Australia. Canberra, A.N.U. Press

Walker, K. F. (1981a). The distribution of freshwater mussels (Mollusca: Pelecypoda) in the Australian zoogeographic region. Pp. 1233-1249 in A. Keast. Ecological Biogeography of Australia. The Hague, Dr W. Junk.

Walker, K. F. (1981b). The distribution of freshwater mussels (Mollusca: Pelecypoda) in the Australian zoogeographic region. Pp. 1233-1249 in A. Keast. Ecological Biogeography of Australia. The Hague, Dr W. Junk.

Walker, K. F. (2004). A guide to the provisional identification of the freshwater mussels (Unionoida) of Australasia. Albury, Murray Darling Freshwater Research Centre.

Walker, K. F., Byrne, M., Hickey, C. W. & Roper, D. S. (2001). Freshwater Mussels (Hyriidae) of Australasia. Pp. 5-31 in G. Bauer & Wächtler, K. Ecology and Evolution of the Freshwater Mussels Unionoida. Ecological Studies. Berlin, Springer-Verlag.

Walker, K. F., Jones, H. A. & Klunzinger, M. W. (2014). Bivalves in a bottleneck: taxonomy, phylogeography and conservation of freshwater mussels (Bivalvia: Unionoida) in Australasia. Hydrobiologia 735:61–79.